Tool Safety

Portable, bench or floor mounted power tools and equipment need routine maintenance, inspection and adjustments to ensure safe operation. Tool bits, blades and other changeable parts must be kept sharp and free from damage. Electrical systems, belts & pulleys and gears must be properly guarded to prevent exposing employees to hazards.

Tool General Safety Precautions:

Employees who use hand and power tools and who are exposed to the hazards of falling, flying, abrasive and splashing objects, or exposed to harmful dusts, fumes, mists, vapors, or gases must be provided with the particular personal equipment necessary to protect them from the hazard. All hazards involved in the use of tools can be prevented by following five basic safety rules:

  • Keep all tools in good condition with regular maintenance.
  • Use the right tool for the job.
  • Examine each tool for damage before use.
  • Operate according to the manufacturer’s instructions.
  • Provide and use the proper protective equipment.

Hand Tools:

Hand tools are non-powered. They include anything from axes to wrenches. The greatest hazards posed by hand tools result from misuse and improper maintenance.Some examples:

• Using a screwdriver as a chisel may cause the tip of the screwdriver to break and fly, hitting the user or other employees.

• If a wooden handle on a tool such as a hammer or an axe is loose, splintered, or cracked, the head of the tool may fly off and strike the user or another worker.

• A wrench must not be used if its jaws are sprung, because it might slip.

• Impact tools such as chisels, wedges, or drift pins are unsafe if they have mushroomed heads.

The heads might shatter on impact, sending sharp fragments flying.Appropriate personal protective equipment, e.g., safety goggles, gloves, etc., should be worn due to hazards that may be encountered while using portable power tools and hand tools.Floors shall be kept as clean and dry as possible to prevent accidental slips with or around dangerous hand tools.Around flammable substances, sparks produced by iron and steel hand tools can be a dangerous ignition source. Where this hazard exists, spark-resistant tools made from brass, plastic, aluminum, or wood will provide for safety.

Basic tips when using hand tools:

  • Always provide training on how to choose the right tool for the job, how to correctly use each tool, and how to identify when tools need repair.
  • Select the right tool for the job. Substitutes increase the chance of having an accident.
  • Use tools designed to allow wrist to stay straight. Avoid using hand tools with your wrist bent.
  • Ensure that employees are properly trained in the safe use of hand tools.
  • Use good quality tools.
  • Keep tools in good condition at all times.
  • Inspect tools for defects before use. Replace or repair defective tools.
  • Keep cutting tools sharp and cover sharp edges with suitable covering to protect the tool and to prevent injuries from unintended contact.
  • Replace cracked, splintered, or broken handles on files, hammers, screwdrivers, or sledges.
  • Ensure that the handles of tools like hammers and axes fit tightly into the head of the tool.
  • Replace worn jaws on wrenches, pipe tools and pliers.
  • Redress burred or mushroomed heads of striking tools.
  • Pull on a wrench or pliers. Never push unless you hold the tool with your palm open.
  • Point sharp tools (e.g., saws, chisels, knives) laying on benches away from aisles and handles should not extend over the edge of the bench top.
  • Maintain tools carefully. Keep them clean and dry, and store them properly after each use.
  • Carry tools in a sturdy tool box to and from the work site.
  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) and well-fitting gloves appropriate for the hazards to which you may be exposed when doing various tasks.
  • Keep the work environment clean and tidy to avoid clutter which may cause accidents.
  • Use a heavy belt or apron and hang tools at your sides, not behind your back.

Power Tool Precautions:

Power tools can be hazardous when improperly used. There are several types of power tools, based on the power source they use: electric, pneumatic, liquid fuel, hydraulic, and powder-actuated.The following general precautions should be observed by power tool users:

The following general precautions shall be observed by power tool users:

  • Never carry a tool by the cord or hose;
  • Never remove prongs from any cords;
  • Never stand in or near water when using tools;
  • Always use a Ground Fault Circuit Interrupter (GFCI) with electrical tools if working in a wet environment;
  • Never “yank” the cord or the hose to disconnect it from the receptacle;
  • Keep cords and hoses away from heat, oil and sharp edges;
  • Replace all frayed and/or damaged extension cords. Do not try to tape cords;
  • Disconnect tools when not in use, before servicing and when changing accessories such as blades, bits and cutters;
  • All observers shall be kept at a safe distance away from the work area;
  • Secure work with clamps or a vise, freeing both hands to operate the tool;
  • Avoid accidental starting. The worker shall not hold a finger on the switch button while carrying a plugged-in tool;
  • Tools shall be maintained with care. They shall be kept sharp and clean for the best performance. Follow instructions in the user’s manual for maintenance, lubricating and changing accessories;
  • Maintain good footing and balance;
  • Avoid loose fitting clothes, ties or jewelry such as bracelets, watches or rings, which can become caught in moving parts;
  • Use tools that are either double-insulated or grounded (three-pronged);
  • Keep work area well lit when operating electric tools;
  • Ensure that cords and hoses do not pose as a tripping hazard; and
  • All portable electric tools that are damaged shall be removed from use and tagged “Do Not Use”. This shall be done by supervisors and/or employees.

Tool Guards:

Hazardous moving parts of a power tool need to be safeguarded. For example, belts, gears, shafts, pulleys, sprockets, spindles, drums, fly wheels, chains, or other reciprocating, rotating, or moving parts of equipment must be guarded. Guards, as necessary, should be provided to protect the operator and others from the following:

  • point of operation,
  • in-running nip points,
  • rotating parts, and
  • flying chips and sparks.

Safety guards must never be removed when a tool is being used. For example, portable circular saws must be equipped with guards. An upper guard must cover the entire blade of the saw. A retractable lower guard must cover the teeth of the saw, except when it makes contact with the work material. The lower guard must automatically return to the covering position when the tool is withdrawn from the work.

Tool Safety Switches:

The following hand-held powered tools are to be equipped with a momentary contact “on-off” control switch: drills, tappers, fastener drivers, horizontal, vertical and angle grinders with wheels larger than 2 inches in diameter, disc and belt sanders, reciprocating saws, saber saws, and other similar tools. These tools also may be equipped with a lock-on control provided that turnoff can be accomplished by a single motion of the same finger or fingers that turn it on.The following hand-held powered tools may be equipped with only a positive “on-off” control switch: platen sanders, disc sanders with discs 2 inches or less in diameter; grinders with wheels 2 inches or less in diameter; routers, planers, laminate trimmers, nibblers, shears, scroll saws and jigsaws with blade shanks ¼-inch wide or less.Other hand-held powered tools such as circular saws having a blade diameter greater than 2 inches, chain saws, and percussion tools without positive accessory holding means must be equipped with a constant pressure switch that will shut off the power when the pressure is released.

Tool Electrical Safety:

Among the chief hazards of electric-powered tools are burns and slight shocks which can lead to injuries or even heart failure. Under certain conditions, even a small amount of current can result in severe injury and eventual death. A shock also can cause the user to fall off a ladder or other elevated work surface.To protect the user from shock, tools must either have a three-wire cord with ground and be grounded, be double insulated, or be powered by a low-voltage isolation transformer. Three-wire cords contain two current-carrying conductors and a grounding conductor. One end of the grounding conductor connects to the tool’s metal housing. The other end is grounded through a prong on the plug. Anytime an adapter is used to accommodate a two-hole receptacle, the adapter wire must be attached to a known ground. The third prong should never be removed from the plug.Double insulation is more convenient. The user and the tools are protected in two ways: by normal insulation on the wires inside, and by a housing that cannot conduct electricity to the operator in the event of a malfunction.

Electric Power Tool General Safety Practices:

  • Electric tools should be operated within their design limitations.
  • Gloves and safety footwear are recommended during use of electric tools.
  • When not in use, tools should be stored in a dry place.
  •  Electric tools should not be used in damp or wet locations.
  • Work areas should be well lighted.

Powered Abrasive Wheel Tools:

Powered abrasive grinding, cutting, polishing, and wire buffing wheels create special safety problems because they may throw off flying fragments. Before an abrasive wheel is mounted, it should be inspected closely and sound- or ring-tested to be sure that it is free from cracks or defects. To test, wheels should be tapped gently with a light non-metallic instrument. If they sound cracked or dead, they could fly apart in operation and so must not be used. A sound and undamaged wheel will give a clear metallic tone or “ring.” To prevent the wheel from cracking, the user should be sure it fits freely on the spindle. The spindle nut must be tightened enough to hold the wheel in place, without distorting the flange.

Power Tool Safety Fact Sheet:

Powered Hand & Portable Tools – OSHA Standard 1910.242Other Portable Tools – OSHA Standard 1910.244Machine Guarding – OSHA Standard 1910.212Grinders – OSHA Standard 1910.215Portable, bench or floor mounted power tools and equipment need routine maintenance, inspection and adjustments to ensure safe operation. Tool bits, blades and other changeable parts must be kept sharp and free from damage. Electrical systems, belts & pulleys and gears must be properly guarded to prevent exposing employees to hazards.

Hazards:

  • Noise.
  • Electric Shock.
  • Amputation.
  • Chemical exposure.
  • Lacerations & Abrasions.
  • Eye Injury from flying particles.
  • Respiratory hazards from dust & cutting fluids.

Personal Protective Equipment Check:

  • Eye protection- clean safety glasses & face shield.
  • Hearing protection for noisy machines & operations.
  • Hand Protection – Leather Work Gloves.
  • Use Proper Respirator when using cutting fluids.
  • Use Proper Respirator for task that produce dust.
  • Use proper gloves when applying any chemical.
  • Wear Safety Glasses when using hand tools.
  • For heavy work & tools – wear steel toed work boots.
  • Use anti-vibration gloves for tools that vibrate

Work Area Safety Check:

  • Well lighted.
  • Not in traffic area.
  • No slip or trip hazards.
  • No standing water.
  • Keep tools off the floor/ground – prevent trips.
  • Rig extension cords above waist level.
  • Don’t block traffic areas with tools.
  • Use warning tape to boundary work areas.
  • Keep work area clear of excessive material & debris

Pre – Use Safety Check:

  • Bench or Floor mounted tool is securely mounted.
  • Check switch not damaged.
  • Check to ensure there are no exposed wires.
  • Cords are free from work area
  • Guards are in place and properly adjusted.
  • Tool casing not cracked or broken.
  • Check grinding wheels are rated for higher speed than machine RPM.
  • Grinder tool rest gap to wheel is no larger than 1/8 inch.
  • Conduct “ring” test for all new grinder stones – ensure no cracks, breaks or chips.
  • Unplug before changing cutting tools.
  • Ensure power tools are grounded or double insulated.
  • Check electric cords for damage.
  • Ensure bits and blades are sharp.
  • Check hose connections for pneumatic tools

Operation Safety:

  • Use a safe position, avoid leaning or over-reaching.
  • Use tool rest – no free hand operations.
  • Dress wheels as needed to prevent buildup and over heating.
  • Stand aside from equipment when starting.
  • Keep hair, sleeves and jewelry out of work area.
  • Replace dull cutting tools.
  • Keep others clear of your immediate area.
  • Pass tools handle first.
  • Don’t use tools in awkward positions.
  • Cover all sharp blades & tools bits.
  • Unplug before adjusting or changing accessories.
  • Keep cords away from heat, oil, and sharp edges.
  • Disconnect tools when not in use.
  • Secure work with clamps or vise.
  • Remove all damaged tools from use.

pneumatic tools:

Pneumatic tools are powered by compressed air. Common types of these air-powered hand tools that are used in industry include buffers, nailing and stapling guns, grinders, drills, jack hammers, chipping hammers, riveting guns, sanders and wrenches.

Use pneumatic tools safely:

  • Review the manufacturer’s instruction before using a tool.
  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles), and, where necessary, safety shoes or boots and hearing protection.
  • Post warning signs where pneumatic tools are used. Set up screens or shields in areas where nearby workers may be exposed to flying fragments, chips, dust, and excessive noise.
  • Ensure that the compressed air supplied to the tool is clean and dry. Dust, moisture, and corrosive fumes can damage a tool. An in-line regulator filter and lubricator increases tool life.
  • Keep tools clean and lubricated, and maintain them according to the manufacturers’ instructions.
  • Use only the attachments that the manufacturer recommends for the tools you are using.
  • Be careful to prevent hands, feet, or body from injury in case the machine slips or the tool breaks.
  • Reduce physical fatigue by supporting heavy tools with a counter-balance wherever possible.

Handle air hoses:

  • Use the proper hose and fittings of the correct diameter.
  • Use hoses specifically designed to resist abrasion, cutting, crushing and failure from continuous flexing.
  • Choose air-supply hoses that have a minimum working pressure rating of 1035 kPa (150 psig) or 150% of the maximum pressure produced in the system, whichever is higher.
  • Check hoses regularly for cuts, bulges and abrasions. Tag and replace, if defective.

    Tool Balancer and Tool

  • Blow out the air line before connecting a tool. Hold hose firmly and blow away from yourself and others.
  • Make sure that hose connections fit properly and are equipped with a mechanical means of securing the connection (e.g., chain, wire, or positive locking device).
  • Install quick disconnects of a pressure-release type rather than a disengagement type. Attach the male end of the connector to the tool, NOT the hose.
  • Do not operate the tool at a pressure above the manufacturer’s rating.
  • Turn off the air pressure to hose when not in use or when changing power tools
  • Do not carry a pneumatic tool by its hose.
  • Avoid creating trip hazards caused by hoses laid across walkways or curled underfoot.
  • Do not use compressed air to blow debris or to clean dirt from clothes.

Dos and Don ts – Power tools:

  • Use the right tool for the job.
  • Inspect tools before each use.
  • Make sure there are guards around points of operation and on/off switches.
  • Be sure that tools are switched off before you plug them in.
  • Turn off and unplug tools before cleaning or changing parts.
  • Use three-prong grounding extension cords with equipment requiring three-prong plugs. Don’t use three-prong cords with two-prong adapters!.

  • Put a power tool down until it has completely stopped running.
  • Use cords to raise or lower equipment.
  • Fasten cords with staples, nails, or other fasteners that could damage cord insulation.
  • Plug or unplug equipment with wet or sweaty hands.
  • Use any tool that has a damaged casing, cord, or plug.
  • Continue to operate a power tool that sparks, smokes, gives a shock, or smells like it’s burning.
  • Get clothes or body parts near the point of operation.
  • Use electric power tools in wet areas unless the tools have been specially approved for.

Dos and Don’ts – Hand Tools:

  • Use tools designed to allow wrist to stay straight. Avoid using hand tools with your wrist bent.
  • Ensure that employees are properly trained in the safe use of hand tools.
  • Use good quality tools and keep tools in good condition at all times.
  • Inspect tools for defects before use. Replace or repair defective tools.
  • Keep cutting tools sharp and cover sharp edges with suitable covering to protect the tool and to prevent injuries from unintended contact.
  • Replace cracked, splintered, or broken handles on files, hammers, screwdrivers, or sledges.
  • Ensure that the handles of tools like hammers and axes fit tightly into the head of the tool.
  • Replace worn jaws on wrenches, pipe tools and pliers.
  • Redress burred or mushroomed heads of striking tools.
  • Pull on a wrench or pliers. Never push unless you hold the tool with your palm open.
  • Point sharp tools (e.g., saws, chisels, knives) laying on benches away from aisles and handles should not extend over the edge of the bench top.
  • Maintain tools carefully. Keep them clean and dry, and store them properly after each use.
  • Carry tools in a sturdy tool box to and from the work site.
  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) and well-fitting gloves appropriate for the hazards to which you may be exposed when doing various tasks.
  • Use a heavy belt or apron and hang tools at your sides, not behind your back.

  • Do not use tools for jobs they are not intended to do. For example, do not use a slot screw drivers as a chisel, pry bar, wedge or punch or wrenches as hammers.
  • Do not apply excessive force or pressure on tools.
  • Do not cut towards yourself when using cutting tools.
  • Do not hold the stock in the palm of your hand when using a cutting tool or a screwdriver.
  • Do not wear bulky gloves to operate hand tools.
  • Do not throw tools. Hand them, handle first, directly to other workers.
  • Do not carry tools in a way that interferes with using both hands on a ladder, while climbing on a structure, or when doing any hazardous work. If working on a ladder or scaffold, tools should be raised and lowered using a bucket and hand line.
  • Do not carry a sharp tool in your pocket.

Click the below link to download tools safety related documents

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 Power tools – Tool box talk

Hand Tools Safety

Hand Tools

A hand tool is any tool that is not a power tool – that is, one powered by hand (manual labour) rather than by an engine. Some examples of hand tools are garden forks, secateurs, rakes, hammers, spanners, pliers, screwdrivers and chisels. Hand tools are generally less dangerous than power tools.

Hand tools are generally classified under the following categories.

  • Clamps
  • Cutting Tools for Bolts, Cables, and Strapping
  • Gear Pullers
  • General Hand Tool Operation
  • Hammers
  • Hand Saw
  • Non-sparking tools
  • Wrenches, Cutters, Reamers, and Threaders
  • Pliers and Wire Cutters
  • Screwdrivers
  • Snips
  • Struck Tools
  • Vises
  • Wood Chisels
  • Wrenches

Clamps :

Clamps are versatile tools that serve to temporarily hold work securely in place. They are used for many applications including carpentry, woodworking, furniture making, welding, construction & metal working.

Clamp styles include C-clamps, bar clamps, pipe clamps, and hand screws. Bar clamps have adjustable arms that are easily widened or narrowed to fit the work piece & therefore, requires fewer turns of the screw spindle, compared to a C-clamp, to hold the piece tightly.

Bar Clamp

Proper use of a bar clamp:

C-Clamp

  • Used for woodwork, especially for holding edges when gluing.
  • Apply clamping pressure at right angles to the glue line otherwise slippage may result.

Proper use of a c-clamp:

Hand Screw Clamp

  • Used for carpentry, welding or cutting.

Proper use of a hand screw clamp:

  • Can be made of metal or wood.
  • Used to hold small pieces or in furniture repair.

General safety tips to know when using clamps:

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).
  • Select the proper clamp style and size by matching the work-holding requirements of the job with the following clamp features:
    • strength and weight (e.g., consider rail size and nominal clamping pressure)
    • opening (length of reach)
    • throat depth (depth of reach)
    • ease of adjustment
    • clamping surfaces (material used and size)
  • Ensure that the swivel at the end of the screw turns freely before using.
  • Dispose of clamps with bent frames; replace bent spindles, if possible.

    Padding

  • Ensure that the pressure plate and anvil parts of the clamp are in full contact with the work piece before tightening.
  • Close the jaws until the clamp feels tight. For example, when gluing, some glue will be squeezed out, a sign that it is tight enough.
  • Use pads with C-clamps to avoid marking the work.
  • Remove clamps as soon as the job is finished. Clamps serve only as temporary devices for holding work securely in place.
  • Keep all moving parts of clamps lightly oiled and keep tools clean to prevent slippage. Also make sure there is no dirt or oil on any part that will come in to contact with the work.
  • Store C-clamps by clamping them in a rack, not in a drawer.

Dont’s on clamps:

  • Do not use extra large clamps just for the sake of their large throats. Instead, use, deep-throat clamps.
  • Do not use any clamps that have a bent frame or a bent spindle.
  • Do not use wrenches, pipes, hammers, or pliers to tighten clamps. Use wrenches only on clamps especially designed for wrenches.
  • Do not hoist or pull with C-clamps. Use special lifting clamps.
  • Do not use C-clamps to construct scaffolds or platforms for workers.

Cutting Tools for Bolts, Cables, and Strapping:

General safety tips to know when using cutting tools:

Many types and sizes of cutters are used for cutting selected metal products made from iron, steel, or softer, non-ferrous materials (e.g., copper, brass, aluminum). Cutters are designed to cut materials of different kinds of products such as wires, cables (electrical, coax, multi-strand), wire ropes, fencing, bolts, rods, pre-stressed concrete wires, and strapping.

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) and protective gloves when using cutters.
  • Choose the proper cutter for the job. Cutters are designed for a specific type, hardness, and size of material.
  • Cut materials straight across – keep the material being cut at right angles to the cutting edges

    Cutting Tools

    of jaws.

  • Prevent injury from flying metal by wrapping a burlap bag, cloth or rag around the cutting jaws. Metal can fly when cut. The harder the metal, the farther it will fly.
  • Warn those in the area to take precautionary measures to avoid possible injury from flying metal pieces.
  • Keep cutting tools in good repair.
  • Adjust and lubricate cutter and moving parts daily if heavily used.
  • Sharpen jaws according to manufacturers’ instructions.

Dont’s :

  • Do not use a cutting tool until you are trained in its proper and safe use.
  • Do not use cushion grip handles for jobs requiring insulated handles. Cushion grips are for comfort primarily and do not protect against electric shock.
  • Do not use cutters which are cracked, broken or loose.
  • Do not exceed the recommended capacity of a tool.
  • Do not cut diagonally.
  • Do not rock cutters from side to side when cutting wire.
  • Do not pry or twist with tool when cutting.
  • Do not hammer on cutting tools or extend the handle length to achieve greater cutting power.
  • Do not expose cutters to excessive heat.
  • Do not repair cutters. Discard equipment that is cracked, broken or shows signs of damage.

Gear Pullers:

Gear pullers are made in various shapes and sizes and have many uses. Always use the correct tool for the job.

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).
  • Select the proper gear puller for each job. Always use a gear puller of the required size or larger. Use a 3-jaw puller, if possible.

    Gear Puller

  • Ensure that the gear puller is aligned with the shaft and fits tightly around the part to be removed. The jaws should be parallel with the screw. This assures a straight pull.
  • Be careful when removing a stubborn gear or bearing. Always strike the head of the centre screw squarely. If after two sharp blows the gear or bearing remains stuck, select a larger puller and proceed to remove the gear or bearing.
  • Use a protective cap or removable point to protect screw from mushrooming or splitting.
  • Stop work if the gear puller starts to deform.
  • Cover work with a cloth to protect you and by-standers from flying parts.
  • Lubricate the centre screw with machine oil before use.
  • Clean the gear puller after use and store it in a dry place.

Dont’s on gear puller:

  • Do not use air powered tools on gear pullers.
  • Do not use any puller with functioning parts that show excessive wear, dents, or cracks. Inspect the centre screw for signs of galling or seizing.
  • Do not heat any gear puller. It will lose its strength and break under pressure if heated.
  • Do not cut or grind any part of a gear puller.

Hammers:

Safety tips to know when using a hammer:

Hammers and other striking tools are widely used and often abused. Hammers are made for specific purposes in various types and sizes, and with striking surfaces of varying hardness. For example, hammers are used for general carpentry, framing, nail pulling, cabinet making, assembling furniture, upholstering, finishing, riveting, bending or shaping metal, striking masonry drill and steel chisels, and so on. Hammers are designed according to the intended purpose.

Glancing Blow

  • Select a hammer that is comfortable for you and that is the proper size and weight for the job. Misuse can cause the striking face to chip, possibly causing a serious injury.
  • Choose a hammer with a striking face diameter approximately 12 mm (0.5 inch) larger than the face of the tool being struck (e.g., chisels, punches, wedges, etc.).
  • Ensure that the head of the hammer is firmly attached to the handle.

    Square Blow

  • Replace loose, cracked or splintered handles.
  • Discard any hammer with mushroomed or chipped face or with cracks in the claw or eye sections.
  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).
  • Strike a hammer blow squarely with the striking face parallel to the surface being struck. Always avoid glancing blows and over and under strikes. (Hammers with bevelled faces are less likely to chip or spall.)

    Hammer

  • Look behind and above you before swinging the hammer.
  • Watch the object you are hitting.
  • Hold the hammer with your wrist straight and your hand firmly wrapped around the handle

Hand Saw:

Saws are made in various shapes and sizes and for many uses. Use the correct saw for the job.

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).
  • Select a saw of proper shape and size for stock being used.

    Hnad Saw - Dimensions

  • Select a saw with the number of teeth per inch (TPI) in order to get the desired finish. For example: a coarse tooth blade (e.g., 2 or 3 TPI) should be used for thicker stock. 18 to 32 TPI should be used on thinner metals or plastic (0.5 cm or 1/4 inch). General wood cutting typically requires about 4 TPI.
  • Choose a saw handle that keeps wrist in a natural position in the horizontal plane.
  • Choose saw with a handle opening of at least 12 cm (5 in.) long and 6 cm (2.5 in.) wide and slanted at a 15° angle.
  • Check the stock being cut for nails, knots, and other objects that may damage or buckle saw.
  • Start the cut by placing your hand beside the cut mark with your thumb upright and pressing against blade. Start cut carefully and slowly to prevent blade from jumping. Pull upward until blade bites. Start with partial cut, then set saw at proper angle.
  • Apply pressure on downstroke only.

    Saw - Cutting Angles

  • Hold stock being cut firmly in place.
  • Use a helper, a supporting bench or vise to support long stock if required.
  • Keep teeth and blades properly set.
  • Protect teeth of saw when not in use.
  • Keep saw blades clean.

Using a hacksaw:

  • Select correct blade for material being cut.
  • Secure blade with the teeth pointing forward. Tighten the nut until the blade is under tension.
  • Keep blade rigid, and frame properly aligned.
  • Cut using steady strokes, directed away from you.
  • Use entire length of blade in each cutting stroke.
  • Use light machine oil on the blade to keep it from overheating and breaking.
  • Cut harder materials more slowly than soft materials.

    Hacksaw

  • Clamp thin, flat pieces requiring edge cutting.
  • Keep saw blades clean and lightly oiled.
  • Do not apply too much pressure on the blade as the blade may break.
  • Do not twist when applying pressure.
  • Do not use when the blade becomes loose in the frame.

Non-sparking tools:

“Non-sparking”, “spark reduced”, “spark-resistant” or “spark-proof” tools are names given to tools made of metals such as brass, bronze, Monel metal (copper-nickel alloy), copper-aluminum alloys (aluminum bronze), or copper-beryllium alloys (beryllium bronze).

Commonly used hand tools are often manufactured of steel alloys. Preferred “non-sparking” metals have less tensile strength than steels usually used to make tools. A lower tensile strength means the metal has less strength or resistance to tearing apart when stretched under test conditions. It also means that these tools are softer, wear down more quickly than ordinary steel tools, and have to be dressed more frequently.

Important thing to know about “non-sparking” tools:

Non-sparking tools also generate sparks sometimes referred to as “cold sparks”. These cold sparks have a low heat level and do not ignite carbon disulfide, which has the lowest ignition point of any substance known to man. Therefore while “non-sparking” tools may lower the risk of a spark, they do not eliminate the possibility of sparks. The name “non-sparking” is misleading because these tools are capable of producing a spark: the term “reduced-sparking tools” better describes these tools.

Non-metals like wood, leather, and plastic are suitable for some tools like shovels, scrapers or scoops and do not pose a friction spark hazard.

Non-sparking tools provide protection against fires and explosions in environments where there is a concern about sparks igniting flammable solvents, vapors, liquids, dusts or residues. There are many standards and recommendations that have been published by OSHA (Occupational Health and Safety Administration) and NFPA (National Fire Protection Association) that advise the use of non-sparking tools in hazardous environments.

NOTE: It is important to assess each situation carefully & use the appropriate tools for the hazards that are present. In some cases, “non-sparking” tools may still be able to produce a spark. Contact the tool manufacturer, and the producer of the flammable material (for example) for recommendations and more information.

Hazards of both “sparking” and “non-sparking” tools?

Both “sparking” and “non-sparking” materials can cause ignition. Two types of hazards are associated with tools manufactured of either material:

  1. Ignition by friction, with impact on each other or on other materials such as steel or concrete, in which an “ordinary” (mechanical or frictional) spark is generated. All tools can ignite flammable mixtures by sparks generated by friction or impact. However, this is true only when the generated spark is incendive: that means a spark that has to have enough heat content (i.e., enough mass and sufficiently high temperature) and has to last long enough to heat a flammable air-vapour mixture above its ignition temperature. This is more likely in the case of sparks formed when using a metal grinder that a spark generated when a hammer strikes some metal.
  2. Ignition by a chemically-generated spark, caused by impact between certain metals and some oxygen-containing substances (such as rust, which is iron oxide).

Use and maintain “non-sparking” tools?

Follow the guidelines below to reduce the risk of explosion and fire.

  • Make sure all “non-sparking” tools are kept clean and free from ferrous or other contaminants, which may hamper the non-sparking properties.
  • Do not use non-sparking hand tools in direct contact with acetylene, which may form explosive acetylides, especially in the presence of moisture.
  • Use local or mechanical ventilation systems as appropriate to remove hazardous materials, dusts and vapors from the workplace.
  • Follow normal safety procedures when sharpening non-sparking tools such as the provision of eye and face protection, adequate extraction and dust collection facilities.

Pipe Tools – Wrenches, Cutters, Reamers, and Threaders:

Pipe tools are made in various shapes and sizes and for many uses. Always use the correct tool for the job.

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles), when necessary.
  • Select a pipe wrench with sufficient capacity and leverage to do the job.
  • Use a pipe wrench to turn or hold a pipe. Never use a pipe wrench to bend, raise or lift a pipe.

Pipe wrench

Pull rather than push on the handle

  • Adjust the pipe wrench grip to maintain a gap between the back of the hook jaw and the pipe. This concentrates the pressure at the jaw teeth, producing the maximum gripping force. It also aids the ratcheting action.
  • Inspect pipe wrenches periodically for worn or unsafe parts and replace them (e.g., check for worn threads on the adjustment ring and movable jaw).
  • Keep pipe wrench teeth clean and sharp.
  • Face a pipe wrench forward. Turn wrench so pressure is against heel jaw.
  • Pull, rather than push on the pipe wrench handle. Maintain a proper stance with feet firmly placed to hold your balance.

Avoid doing when using pipe wrenches?

  • Do not use a pipe wrench as a hammer, or strike a pipe wrench with a hammer.
  • Do not use pipe wrenches on nuts and bolts.
  • Do not use a pipe extender for extra leverage. Get a larger pipe wrench.

Safety tips for using pipe cutters, reamers, threaders:

  • Replace pipe cutter wheels which are nicked or otherwise damaged.
  • Use a 3- or 4-wheeled cutter, if there is not enough space to swing the single wheel pipe cutter completely around the pipe.
  • Choose a cutting wheel suitable for cutting the type of pipe material required:
    • Thin wheel for cutting ordinary steel pipe.
    • Stout wheel for cutting cast iron.
    • Other wheels for cutting stainless steel, plastic and other materials.
  • Select the proper hole diameter and correct tap size to tap a hole. The hole should be sized so that the thread cut by the tap will be about 75% as deep as the thread on the tap.
  • Use a proper tap wrench (with a “T” handle) for turning a tap.
  • Use lubricant or machine cutting fluid with metals other than cast iron.

Dont’s

  • Do not allow chips to clog the flutes (groves in the tap that allow metal chips to escape from the hole). The chips may prevent the tap from turning – this may result in the tap breaking if you continue to apply pressure.
  • Do not use a conventional adjustable wrench for turning a tap – it will cause uneven pressure on the tap that may cause it to break.
  • Do not attempt to thread hardened steel. This can chip or damage the die.
  • Do not thread any rod or other cylindrical object that is larger in diameter than the major diameter of the die thread.
  • Do not use a spiral reamer on a rotating pipe. The reamer may snag and cause serious injury.

Pliers and Wire Cutters:

Pliers are made in various shapes and sizes and for many uses. Some are used for gripping something round like a pipe or rod, some are used for twisting wires, and others are designed to be used for a combination of tasks including cutting wire. There are also tools that are used just for cutting wires (as opposed to wire cable and rope). Use the correct pliers or wire cutters for the job.

Side Cutting Pliers

Proper use of side cutting (lineman’s) pliers:

  • Many applications including electrical, communications and construction work.
  • Use to grip, splice or cut wires, and strip insulation.

Long Nose Pliers

Proper use of long nose pliers:

  • Use to grip small objects, reach awkward places, holding wires, bend loops, and attach wires.
  • Work involving smaller gauge wire.

Utility Pliers

Proper use of utility pliers:

  • Use to grip round square, flat and hexagonal objects.
  • Can apply limited torque (twisting force) without damaging the work.

Diagonal Cutting Pliers

Proper use of diagonal cutting pliers:

  • For work involving cutting and skinning wires, cutting and removing pins, nails and other fasteners.

Flat Nose Pliers

Proper use of flat nose pliers:

  • Common pliers, used in many applications and assembly work.
  • Use to grip, turn and bend wires.

Slip Joint Pliers

Proper use of slip joint pliers:

  • Used to adjust nuts or bolts.

End Cutting Pliers

Proper use of end cutting pliers

  • Use for cutting wires, nails, rivets close to work.

Safety tips to know when using pliers and wire cutters:

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) whenever there is a potential hazard from flying particles, pieces of wire, etc.
  • Cut at right angles. Never rock the cutting tool from side to side or bend wire back and forth against the cutting edges.
  • Choose pliers or wire cutters that have a grip span of 6 cm – 9 cm (2 1/2 – 3 1/2 in.) to prevent your palm or fingers from being pinched when the tools are closed.
  • Use adjustable pliers that allow you to grip the workpiece firmly while maintaining a comfortable handgrip (i.e., hand grasp is not too wide).
  • Use tools only if they are in good condition.
  • Make sure that the cutting edges are sharp. Dull and worn down cutting edges require many times more force needed for cutting.
  • Make sure that the toothed jaws are clean and sharp. Greasy or worn down jaws can result in compromised safety. Such tools also require increased force to hold the workpiece which, in turn, increases the risk of muscular fatigue and repetitive strain injuries.
  • Oil pliers and wire cutters regularly. A drop of oil on the hinge will make the tools easier to use.
  • Pull on the pliers; do not push away from you when applying pressure. If the tools slips unexpectedly, you may lose your balance or hit your hand against equipment or something else hard that could result in an injury.

Dont’s on pliers and wire cutters:

  • Do not cut hardened wire unless the pliers or wire cutters are specifically manufactured for this purpose.
  • Do not expose pliers or wire cutters to excessive heat.
  • Do not bend stiff wire with light pliers. Needle nose pliers can be damaged by using the tips to bend large wire. Use a sturdier tool.
  • Do not use pliers as a hammer.
  • Do not hammer on pliers or wire cutters to cut wires or bolts.
  • Do not extend the length of handles to gain greater leverage. Use a larger pair of pliers for gripping or a bolt cutter for cutting.
  • Do not use cushion grip handles for jobs requiring tools with electrically insulated handles. Cushion grips are for comfort primarily and do not protect against electric shock.
  • Do not use pliers on nuts and bolts; use a wrench.

Screwdrivers:

Screwdrivers are made in various shapes and sizes and for many uses. Use the correct screwdriver for the job.

  • Always match the screwdriver to the screw head, both in terms of size and type.
  • Choose contoured handles that fit the shank tightly, with a flange to keep the hand from slipping off the tool.
  • Use a slot screwdriver with a blade tip width that is the same as the width of slotted screw head.
  • For cross head screws, use the correct size and type of screwdriver: a Phillips screwdriver may slip out of a screw head designed for use with the slightly, flatter-tipped Pozidriv screwdriver.
  • Use a vise or clamp to hold the stock if the piece is small or moves easily.
  • Wear safety glasses or a face shield (with safety glasses or goggles) that is appropriate for the hazards of the work you are doing.Offset Screwdriver
  • Keep the screwdriver handle clean. A greasy handle could cause an injury or damage from unexpected slippage.
  • Shut off electricity before beginning work on electrical equipment (lock out, de-energize and tag out).
  • If work must be carried out on “live” equipment, use screwdrivers that have insulated handles designed for electrical work and a non-conducting shaft.  Remember, most plastic handles are designed for grip and comfort.
  • Use non-magnetic tools when working near strong magnets (e.g., in some laboratories).
  • Use a screw-holding screwdriver (with screw-holding clips or magnetic blades) to get screws started in awkward, hard-to-reach areas. Square-tipped screwdrivers (e.g., Robertson) that hold screws with recessed square holes are also useful in such situations.
  • Use an offset screwdriver in close quarters where a conventional screwdriver cannot be used.

Offset Screwdriver:

  • Use a screwdriver that incorporates the following features when continuous work is needed:
    • A pistol grip to provide for a straighter wrist and better leverage.
    • A “Yankee drill” mechanism (spiral ratchet screwdriver or push screwdriver) which rotates the blade when the tool is pushed forward.
    • A ratchet device to drive hard-to-move screws efficiently.Yankee Drill Mechanism with a Pistol Grip
  • Or use a powered screwdriver.

Yankee Drill Mechanism with a Pistol Grip

  • File a rounded tip square making sure the edges are straight. A dull or rounded tip can slip out of the slot and cause hand injury or damage to materials.
  • Store screwdrivers in a rack or partitioned pouch so that the proper screwdriver can be selected quickly.

Dont’s on screwdriver:

  • Do not lean or push on a screwdriver with any more force than necessary to keep contact with the screw. A screw properly piloted and fitted will draw itself into the right position when turned. Keep the shank directly over the screw being driven.
  • Do not hold the stock in one hand while using the screwdriver with the other. If the screwdriver slips out of the slot, you may cut your hand.
  • Do not hammer screws which cannot be turned.
  • Do not grind the tip to fit all sizes of screw heads.
  • Do not try to use screwdrivers on screw heads for which they are not designed (e.g., straight blade screwdrivers on Phillips, clutch head, Torx or multi-flutted spline screw heads).
  • Do not use defective screwdrivers (i.e., ones with rounded or damaged edges or tips; split or broken handle; or bent shaft).
  • Do not use a screwdriver for prying, punching, chiseling, scoring, scraping or stirring paint.
  • Do not use pliers on the handle of a screwdriver for extra turning power. A wrench should only be used on the square screwdriver shank designed for that purpose.
  • Do not expose a screwdriver blade to excessive heat. Heat can affect the temper of the metal and weaken the tool.
  • Do not use a screwdriver to check if an electrical circuit is live. Use a suitable meter or other circuit testing device.
  • Do not carry screwdrivers in your pockets.

Snips:

Snips are made in various shapes and sizes for various tasks. The handle can be like those on scissors with finger and thumb holes or like plier handles. Models are available for cutting in straight lines, in curves to the left or curves to the right.

  • Universal snips can cut in both straight and wide curves.
  • Straight snips and duckbill snips (flat blade, “perpendicular” to the handle, with pointed tips) are designed to cut in straight lines; some duckbill snips are designed for cutting curved lines.
  • Hawk’s bill snips (with crescent-shaped jaws) are used for cutting tight circles.
  • Aviation snips have compound leverage that reduces the effort required for cutting.
  • Offset snips have jaws that are set at an angle from the handle.

DO

  • Select the right size and type of snips for the job; check the manufacturer’s specifications about the intended use of the snips (e.g., type of cut – straight, wide curve, tight curve, right or left, and maximum thickness and kind of metal or other material that can be cut).
  • Only use snips that are sharp and in good condition.
  • Wear safety glasses or goggles, or a face shield (with safety glases or goggles) and protective gloves when working with snips. Small pieces of metal may go flying in the air and the cut edges of metal are sharp.

Left cut snips are for making cuts to the left and straight cuts.

Left / Right Cut Snips

Right cut snips are for making straight cuts and cuts to the right.

Offset snips permit you to keep your hands safely above the cut while cutting directly through the centre of a large sheet.

  • Use snips for cutting soft metal only. Hard or hardened metal should be cut with cutting tools designed for that purpose.
  • Use ordinary hand pressure for cutting. If extra force is needed, use a larger tool.
  • Cut so that the waste is on the right if you are right-handed or on the left if you are left-handed.
  • Avoid springing the blades. This results from trying to cut metal that is too thick or heavy for the snips you are using.
  • Keep the nut and the pivot bolt properly adjusted at all times.
  • Oil the pivot bolt on the snips occasionally.
  • Use the locking clip (if available) to keep the snips closed when not in use.

Dont’s on snips:

  • Do not try to cut sharp curves with straight cut snips.
  • Do not cut sheet metal thicker than the manufacturer’s recommended upper limit (e.g., cuts up to 16 gauge cold rolled steel or 18 gauge stainless steel).
  • Do not extend the length of handles to gain greater leverage.
  • Do not hammer or use your foot to exert extra pressure on the cutting edges.
  • Do not use cushion grip handles for tasks requiring insulated handles. They are for comfort primarily and not for protection against electric shocks.
  • Do not attempt to resharpen snips in a sharpening device designed for scissors, garden tools or cutlery.

Struck Tools:

Safety tips to know when using a struck tool:

Struck tools are made in various shapes and sizes and for many uses and include cold chisels, punches, nail sets, rock and star drills, and wedges. Use the correct tool for the job.

DO

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).

    sponge rubber shield

  • Use the tools only if they are good condition (i.e., cutting edges are sharp, struck head is not mushroomed or chipped).
  • Hold the chisel, for shearing and chipping, at an angle which permits the bevel of the cutting edge to lie flat against the shearing plane.
  • Provide hand protection
  • Hand protection can be provided by a sponge rubber shield forced onto the shaft of a chisel or select struck tools that come with hand protectors designed for the tool.

    mushroomed head tool

  • Punch and chisel holders are also available.
  • Discard tools which are bent, cracked or chipped.
  • Redress striking tools with burred or mushroomed heads.

Redress the point or cutting edge to its original shape. Grind to a slightly convex cutting edge. The point angle of the chisel should be 70° for hard metals, 60° for soft.

Dont’s on struck tool:

chisel

  • Do not use struck tools if the struck end is chipped or mushroomed.
  • Do not use struck tools if the cutting edge is dull or chipped or if the point of a punch is slanted or damaged.
  • Do not apply too much pressure to the head when grinding a chisel. The heat generated can remove the temper. Immerse the chisel in cold water periodically when grinding.
  • Do not use cold chisels for cutting or splitting stone or concrete.

    chisel holder

  • Do not use a drift pin punch (also called an aligning punch) as a pin punch intended for driving, removing, or loosening pins, keys, and rivets.
  • Do not allow bull point chisels to be hand-held by one employee and struck by another. Use tongs or a chisel holder to guide the chisel so that the holder’s hand will not be injured.

Vises:

A vise, sometimes called the third hand, is an indispensable tool in the tool room or workshop. Vises are usually mounted on workbenches or similar firm supports to hold material in place.

Most vises can be used for a wide variety of work. Select the most suitable vise which is strong enough for the work.

  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) when using striking tools or power tools on a workpiece held by a vise.
  • Attach a vise securely. Place bolts in all the holes in the base of the vise. Use lock washers under the nuts.
  • Mount a vise so that the stationary jaw projects slightly beyond the edge of the workbench. This allows long work to be clamped in the vise without interference from the edge of the workbench.
  • Ensure that the workbench is firmly secured to its base.

Vise

  • Check the vise for cracks or other damage before clamping a workpiece in it.
  • Use a vise large enough to hold the work without strain.
  • Place the workpiece in the vise so that the full clamping surface of the jaw supports the workpiece.
  • Keep the workpiece in the vise close as possible to the jaws to prevent vibration when sawing, filing, etc.
  • Support the end of extra long work with an adjustable stand, saw horse, or box rather than putting extra strain on the vise.
  • Keep all threaded and moving parts clean, oiled and free of chips and dirt.
  • Use jaw liners in a vise where there is any possibility of marking the work.
  • Replace a bent handle and worn jaw inserts.

Dont’s on vise:

  • Do not weld the base of the vise to any metal.
  • Do not repair a vise by welding or brazing.
  • Do not try to bend a heavy rod in a light vise.
  • Do not cut into the jaws.
  • Do not apply heavy pressure at the corner of the vise jaws.
  • Do not use a handle extension (e.g., a pipe) for extra clamping pressure.
  • Do not hammer on the handle to tighten beyond hand pressure.
  • Do not use the jaws of the vise as an anvil.
  • Do not use any vise that has the slightest crack.
  • Do not unscrew or open the jaws of the vise wider than they were designed to be used.

Wood Chisels:

Wood chisels are made in various shapes and sizes and for many uses. Use the correct chisel for the job.

  • Wear safety glasses, or goggles, or a face shield (with safety glasses or goggles).
  • Use the right size of chisel for the job.
  • Choose smooth, rectangular handles that have no sharp edges and are attached firmly to the chisel.
  • Ensure that the cutting edge is sharp. Dull chisels can be difficult to control and require more effort to do the job.
  • Check stock thoroughly for knots, staples, nails, screws or other foreign objects before chiseling.
  • Clamp stock so it cannot move.

    wood chisel

  • Adjust your stance so that you do not lose your balance if the tool slips.
  • Chip or cut away from yourself.
  • Keep your hands and body behind the cutting edge.
  • Use a wooden or plastic mallet with a large striking face on all chisels. Only heavy-duty or framing chisels are made of a solid or molded handle that can be struck with a steel hammer.
  • Make finishing or paring cuts with hand pressure alone.
  • Place chisels safely within the plastic protective caps to cover cutting edges when not in use.
  • Replace any chisel that is bent or shows dents, cracks, chips, or excessive wear.
  • Store chisels in a “storage roll,” a cloth or plastic bag with slots for each chisel, and keep them in a drawer or tray.
  • Replace broken or splintered handles.
  • Sharpen cutting edges as often as necessary.

Don t’s on Chisels:

  • Do not use a wood chisel as a pry or a wedge.
  • Do not use a wood chisel on metal.
  • Do not use an all-steel chisel with a mushroomed face or a chipped edge. Redress with a file or whetstone.
  • Do not use a grinder to redress heat-treated tools. Use a whetstone.
  • Do not use a dull chisel.

Wrenches:

Wrenches are made in various shapes and sizes and are used for gripping, fastening, turning, tightening and loosening things like pipes, pipe fittings, nuts and bolts. There basically two major kinds of wrenches:

  • Pipe wrenches used in plumbing for gripping round (cylindrical) things.
  • General use wrenches used on nuts and bolts that have flat, parallel surfaces; e.g., square or hexagonal (hex).

Wrenches may be adjustable to fit different sized pipes, nuts and bolts or may be a fixed size.

Adjustable wrenches include:

  • Pipe wrenches.
  • Crescent (TM) wrenches which have adjustable jaws set at a 30 degree angle from the handle. Although Crescent is a trade name, it is widely used to refer to any regular adjustable wrench with an angled jaw regardless of who manufactured it.
  • Monkey wrenches which have their adjustable head at a 90 degree angle from the handle.

Fixed-sized wrenches include:

  • Open ended wrenches that have “jaws” with parallel sides or tines that fit snugly on nuts and bolts.
  • Closed end or box wrenches that have a loop at the end with notches on the inside that allow the wrench to fit either square or hex nuts or both (depending on the number of notches or points).
  • Combination wrenches that have both an open end and a closed end on either end of the wrench; usually they fit the same size nut or bolt.
  • Socket wrenches are like closed end wrenches except they are cylindrical in shape. They can fit over a nut in a recessed hole that would be inaccessible with open or closed ended wrenches. These have an offset handle at right angles to the nut being tightened or loosened. Usually the handle is a ratchet-type handle that allows the user to turn the socket continuously in one direction by moving the handle back and forth without having to take the socket off the nut.
  • Torque wrenches, one type of socket wrenches, have a built-in spring-loaded indicator that shows how much torque being is being applied (i.e., shows how hard the nut is being tightened).
  • Nut drivers, another type of socket wrenches, are sockets that can be snapped on or permanently fixed to a screwdriver-type handle.
  • Allen wrenches or Allen keys are hexagon-shaped (six-sided) metal shafts that are bent into an L-shape for leverage. Hex drivers are “straight Allen wrenches” that have a screwdriver-type handle. These are different from the other wrenches since they fit inside a recessed hexagonal hole in screw heads instead of around a nut or bolt.

Fixed wrenches fit single, specific sizes. Metric wrench sizes are expressed as whole numbers (e.g., 8, 10, 14, 32) that correspond to the sizes in millimetres. Non-metric sizes used widely in the U.S. are also called S.A.E (Society of Automotive Engineers) sizes and are expressed as fractions of an inch; e.g., 1/4, 1/2, 3/4, 1 1/4. Since both metric and S.A.E. fasteners (nuts, bolts, etc.) are used in Canada, users must select the correct type and size of wrench to prevent injuries and damage to equipment in case of slippage when force is applied to the wrench.

General safety tips when using wrenches:

  • Use the correct wrench for the job – pipe wrenches for pipes plumbing fittings, and general use wrenches for nuts and bolts.
  • Discard any damaged wrenches (e.g., open ended wrenches with spread jaws or box wrenched with broken or damaged points).
  • Select the correct jaw size to avoid slippage.
  • Wear safety glasses or a face shield (with safety glasses or goggles) where there is a likely hazard of flying particles or falling debris.
  • Position your body in a way that will prevent you from losing balance and hurting yourself if the wrench slips or something (e.g., a bolt) suddenly breaks.
  • Use a box or socket wrench with a straight handle, rather than an off-set handle, when possible.
  • Ensure that the jaw of an open ended wrench is in full contact (fully seated, “flat”, not tilted) with the nut or bolt before applying pressure.
  • When turning with an adjustable wrench, the direction of the turn should be against (towards) the permanent jaw.
  • Ensure that the teeth of a pipe wrench are sharp and free of oil and debris and that the pipe or fitting is clean to prevent unexpected slippage and possible injuries.
  • Apply a small amount of pressure to a ratchet wrench initially to ensure that the ratchet wheel (or gear) is engaged with the pawl (a catch fitting in the gear) for direction you are applying pressure.
  • Support the head of the ratchet wrench when socket extensions are used.
  • Pull on a wrench using a slow, steady pull; do not use fast, jerky movements.
  • Stand aside when work is done with wrenches overhead.
  • Make sure adjustable wrenches do not “slide” open during use.
  • Keep tools well maintained (cleaned and oiled).
  • Clean and place tools and wrenches in a tool box, rack or tool belt after use.

Don t’s on wrenches:

  • Do not use push on a wrench – losing your balance is more likely if the wrench slips.

    Do not strike a wrench with a hammer

  • Do not use a wrench that is bent handle or damaged.
  • Do not use worn adjustable wrenches. Inspect the knurl, jaw and pin for wear.
  • Do not pull on an adjustable wrench that is loosely adjusted.
  • Do not use pipe wrenches on nuts or bolts.
  • Do not use pipe wrenches for lifting or bending pipes.
  • Do not use a wrench on moving machinery.
  • Do not use the wrong tools for the job. Never use pliers instead of a wrench or a wrench as a hammer.
  • Do not use a make-shift wrench.
  • Do not insert a shim in a wrench for better fit.
  • Do not strike a wrench (except a “strike face” wrench) with a hammer, or similar object, to gain more force.

Dos and Don’ts – Hand Tools:

  • Use tools designed to allow wrist to stay straight. Avoid using hand tools with your wrist bent.
  • Ensure that employees are properly trained in the safe use of hand tools.
  • Use good quality tools and keep tools in good condition at all times.
  • Inspect tools for defects before use. Replace or repair defective tools.
  • Keep cutting tools sharp and cover sharp edges with suitable covering to protect the tool and to prevent injuries from unintended contact.
  • Replace cracked, splintered, or broken handles on files, hammers, screwdrivers, or sledges.
  • Ensure that the handles of tools like hammers and axes fit tightly into the head of the tool.
  • Replace worn jaws on wrenches, pipe tools and pliers.
  • Redress burred or mushroomed heads of striking tools.
  • Pull on a wrench or pliers. Never push unless you hold the tool with your palm open.
  • Point sharp tools (e.g., saws, chisels, knives) laying on benches away from aisles and handles should not extend over the edge of the bench top.
  • Maintain tools carefully. Keep them clean and dry, and store them properly after each use.
  • Carry tools in a sturdy tool box to and from the work site.
  • Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) and well-fitting gloves appropriate for the hazards to which you may be exposed when doing various tasks.
  • Use a heavy belt or apron and hang tools at your sides, not behind your back.

  • Do not use tools for jobs they are not intended to do. For example, do not use a slot screw drivers as a chisel, pry bar, wedge or punch or wrenches as hammers.
  • Do not apply excessive force or pressure on tools.
  • Do not cut towards yourself when using cutting tools.
  • Do not hold the stock in the palm of your hand when using a cutting tool or a screwdriver.
  • Do not wear bulky gloves to operate hand tools.
  • Do not throw tools. Hand them, handle first, directly to other workers.
  • Do not carry tools in a way that interferes with using both hands on a ladder, while climbing on a structure, or when doing any hazardous work. If working on a ladder or scaffold, tools should be raised and lowered using a bucket and hand line.
  • Do not carry a sharp tool in your pocket

Click the below link to download hand tools safety materials

hand-safety-a

hand-safety-toolkit

handtools-equipment

Abrasive Wheel Safety

Abrasive Wheel

Introduction:

The purpose of this guidance is to give advice on precautions for the prevention of accidents in the use of abrasive wheels, in particular injury resulting from either wheel breakage or contact with a running wheel. For the duties of those people using abrasive wheels to be fully understood, the guidance should be read in conjunction with the Approved Code of Practice (ACOP).

The risk of breakage is inherent in every abrasive wheel. If the number of breakages is to be kept low, the initial care exercised in the design, manufacture and testing by abrasive wheel and machine makers must be coupled with the adoption of safety measures by the users. Accident statistics indicate that nearly half of all accidents involving abrasive wheels are due to an unsafe system of work or operator error.

Abrasive wheel characteristics:

An abrasive wheel is usually defined as a wheel consisting of abrasive particles bonded together with various substances. There are two main types of bonding agent: inorganic and organic.

Inorganic bonds are mainly vitrified, ie the wheel is generally fired in a furnace to give the bond a hard, strong but brittle structure. These wheels are used for precision grinding applications as they hold their shape, but require dressing.

Organic bonds are not fired but are cured at low temperature; the bond agents are resinous (B), rubber (R) and shellac (E). Such wheels are tough, shock-resistant and self-dressing, and are most suited to non-precision applications, for example fettling and cutting off.

The following words in bold are the variable elements in abrasive wheel manufacture.

(a) Abrasive means the type of abrasive used in wheel construction;

(b) Grain/grit size means the particle size of abrasive grains. The range is expressed by number (very coarse 4 to very fine 1200);

(c) Grade represents the tenacity with which the bonding material holds the abrasive grain in a wheel. Wheels are graded as ‘soft’ or ‘hard’ according to their degree of tenacity. The grade scale is expressed in letters from A (extremely soft) to Z (extremely hard);

(d) Structure means the level of porosity in the wheel. The higher the number, the greater the level of porosity;

(e) Bond type means the bonding material used in the wheel construction.

Abrasive wheel marking system:

Maximum permissible speed

13 The maximum permissible speed in revolutions per minute (rpm) and meters per second (m/s) specified by manufacturers should be marked on every abrasive wheel larger than 80 mm in diameter, or on the blotter or identification label which is sometimes attached to it. Since it is not practicable to mark smaller wheels, the maximum permissible speed in rpm of wheels 80 mm in diameter or less should be stated in a notice posted in a position where it can easily be read. For speeds of 50 m/s and above, color-coded stripes will appear on the wheel.

Restrictions of use

Specify how wheels should be marked to indicate specific restrictions for use. These are:

(a) RE1: Not permitted for hand-held and manually guided grinding;
(b) RE2: Not permitted for hand-held cutting-off machines (see Figure 1);
(c) RE3: Not suitable for wet grinding;
(d) RE4: Only permitted for totally enclosed working area;
(e) RE6: Not permitted for face grinding.

Figure-1

Shelf life

All organic bonded wheels for hand-held applications will bear a use-by date of three years from the date of manufacture.

Traceable number

A code number should be marked on the wheel to indicate the source and manufacturing details of the wheel.

Wheel breakage

Abrasive wheel manufacturers take all reasonable precautions, including speed tests, to supply sound wheels, and various methods are used in their construction to reduce the risk of breakage. These include:

(a) Fibre reinforcement: This is normally a resin-coated, woven, glass-fibre mat used in organic wheels (resinoid and rubber bonded) for heavy-duty grinding and cutting operations. It allows the wheel to withstand high stresses and helps to contain fragments if the wheel breaks in use;

(b) Steel rings: These are moulded into the wheel close to the bore and are designed to retain wheel fragments if breakage occurs when the wheel is near to throwaway size. They can also be used to prevent excessive wear on the wheel;

(c) Safety inserts: These are threaded nuts incorporating locking teeth and form part of a plate which strengthens the base of a cup wheel used for portable grinding. They serve merely as an additional safety device and may not replace the guard;

(d) Tapewinding: Adhesive tape, glass-fiber or metallic wire may be used to strengthen thin-walled cup and cylinder wheels. In the event of breakage, they help to hold the fragments together;

(e) Fine grit center or similar: A fine grit center is placed around the bore to increase the strength of a vitrified grinding wheel. The center is molded together with the wheel. The bore area may also be impregnated by epoxy resin to increase the strength of the wheel. These two types of reinforcement are used for wheels operating at 63 m/s to 125 m/s.

In spite of these precautions breakage may occur in service due to a defect caused by subsequent misuse or handling. Bad storage, incorrect selection of a wheel, improper mounting, excessive out-of-balance conditions, excessive speed, grinding machine defects, and malpractices in the grinding operations are all factors that can result in breakage. Two or more of these factors may operate together, and it is essential that every breakage of a wheel should be followed by careful investigation, to establish the cause of the breakage and take suitable action to prevent a recurrence.

Examination, handling and storage of abrasive wheels

Examination

Wheels should be carefully unpacked, cleaned with a brush and examined for possible damage in transit. In unpacking, the careless use of a tool may cause damage to the wheel. The soundness of wheels can be further checked by tapping them with a light, non-metallic implement. This is known as the ‘ring’ test. Wheels must be dry and free from sawdust for the ring test otherwise the sound will be deadened. It should also be noted that organic bonded wheels do not emit the same clear metallic ring as inorganic bonded wheels. Heavy wheels should be supported on a clean hard floor for the ring test while light wheels should be suspended from their hole on a finger or small pin. If the wheel sounds dead, for example due to cracking, it should not be used.

Comparison with other wheels of the same lot and specification will allow rejection of any wheel with a suspiciously different ring before use. In case of doubt, the manufacturer should be notified. The ring test is not practicable with the following types of wheels because of their shape or size, so extra care and vigilance is required during the visual examination:

(a) small wheels (100 mm diameter and smaller);
(b) plugs and cones;
(c) mounted wheels;
(d) segments;
(e) plate-mounted wheels;
(f) inserted nut disc and cylinder wheels.

Handling

All abrasive wheels are relatively fragile. It should not be assumed that organic bonded wheels (resin, shellac, rubber) will stand rough handling. The following rules should be observed to avoid chipping, cracking and breakage:

(a) handle wheels carefully to prevent dropping or bumping. Do not roll abrasive wheels. Where this is unavoidable because of the large size of the wheel, a soft, resilient floor surface is essential.

(b) use trucks or suitable conveyors which will provide proper support for transporting wheels which cannot be carried by hand (Figures 2 and 3). Stack and support wheels carefully on trucks so that they will not topple over and be damaged. Do not pile heavy castings or tools on top of abrasive wheels.

Figures 2 and 3 When handling large wheels use a truck or other suitable conveyance. They should not be rolled along the floor unless a suitable mat or other protection is available.

Storage

Suitable racks, bins or compartmented drawers should be provided to accommodate the various types of wheels used. The following suggestions covering the design of facilities may be helpful. Most plain and tapered wheels are best supported on their edges or on a central support.
21 Where the wheels are placed on their edges, the support should take the form of a cradle to prevent rolling, with a sufficient number of partitions to prevent wheels from falling over. To prevent warping, thin, organic bonded wheels such as those used for cutting-off should be laid flat on a horizontal surface of steel or similar rigid material away from excessive heat and moisture. Blotters or other packing should not be placed between stacked thin wheels. However, if the wheels are supplied with blotters attached, suitable separators should be used to preserve flatness. Cylinder wheels and large, straight cup wheels may be stacked on the flat side with corrugated cardboard or other cushioning material between them, or they may be stored in racks similar to those used for large, straight wheels. To prevent chipping of edges, taper cup wheels are best stored as shown in the illustration of a typical storage rack (Figures 4a and 4b).

Figures 4a

Figures 4b

To minimize deterioration, wheels must be stored in a room which is dry and not subject to extreme temperatures. It is recommended that wheels should be marked with the date they are received from the supplier. Older wheels should be issued before newer wheels and if there is any doubt, or if wheels have been in stock for more than three years, the manufacturer should be consulted about their suitability for use.

Selecting the correct wheel for the job is essential for safety. A grinding wheel may be dangerous if used for an application for which it is not intended. It is therefore essential that the fullest details of the type of grinding operation should be given to the manufacturer to enable the correct wheel to be supplied.

As a rough guide, soft wheels are preferred on hard material and hard wheels on soft material. With wheels of unsuitable structure for the job, ‘loading’ may result, ie the abrasive wheel face becomes clogged with particles of the material being ground. A wheel may also be either too hard or too fine, resulting in ‘glazing’. The operator is then tempted to use excessive pressure for the work on the wheel, a contributory cause of wheel breakage. Each type of wheel has its uses and is best suited to certain classes of work. The best policy in selecting grinding machinery is to consult machines and abrasive wheels manufacturers and not to experiment without competent advice.

Speed

Remember that centrifugal force (the ultimate cause of wheel bursts) increases not directly with speed, but as the square of the speed. The speed at which the abrasive wheel revolves is, therefore, extremely important. It cannot be too strongly emphasized that doubling the speed increases fourfold the stress in the wheel and hence the risk of the wheel bursting.

Peripheral and rotational speed

The maximum operating speed is marked on every wheel in two ways:

(a) the peripheral surface speed which is given in m/s;
(b) the rotational speed which is given in rpm.

As the wheel wears down in use, the effective peripheral surface speed will reduce if the rotational speed remains constant and may result in a reduced grinding efficiency. To counteract this, the spindle speed can be increased, providing the maximum peripheral surface speed of the wheel is not exceeded. Always ensure that the spindle speed is reduced to its original value before fitting new wheels.

Never operate new abrasive wheels at speeds (in rpm) in excess of that marked on the wheel. Overspeeding is one of the main causes of wheel breakage. To illustrate the point, a fragment from a burst wheel operating at 35 m/s is travelling at 80 mph (126 km/hr) and for 125 m/s at 280 mph (450 km/hr).

Grinding machine

Abrasive wheels should not be mounted on makeshift apparatus. They should be mounted on the type of machine for which they are intended. These appear to be obvious precautions, but accidents still occur because wheels are mounted on home-made or improvised apparatus quite unsuitable for the work. Likewise, accidents are caused by heavy wheels being fitted to spindles designed to take only the lightest of wheels. As a result, vibration is excessive and breakages occur. On no account should an abrasive wheel be screwed on to the tapered spindle of a buffing machine. This dangerous method of mounting is likely to result in the breaking of the wheel owing to the wedging action of the tapered spindle.

Pedestal grinders should be heavily built and mounted on good foundations. Bench grinders should be securely anchored to a stout bench.

Spindles

The spindle should be long enough and threaded to a sufficient length to ensure that when the wheel and flanges are mounted, there will be enough thread for full engagement of the nut on the spindle. The thread should extend inside the flange but not into the hole in the wheel. When the wheel is secured by means of a single central spindle nut, the thread should be such that the direction of tightening the nut is opposite to the direction of rotation of the wheel to ensure that the nut will not come loose as the wheel rotates.

Machine bearings

Machine bearings should be maintained in good condition, free from play and adequately lubricated. Loose bearings or any other factor causing an out-of-balance condition will produce vibration and may cause the wheel to knock against the work excessively with the eventual risk of wheel breakage. In addition, heat generated by machine bearings in poor condition can be transmitted to the spindle causing thermal expansion which may result in cracking of the abrasive wheel.

Speed control

In no circumstances should the maximum permissible operating speed specified by the wheel manufacturers be exceeded.The maximum speed of the spindle should be marked on every grinding machine so that it is easy to compare the speed marked on the wheel with the speed of the machine spindle. Where the spindle can be operated at more than one specific speed, each speed must be shown, and if the speed is infinitely variable within a specified range, the notice must show the maximum and minimum speeds.

Insufficient power

Inadequate power at the grinding wheel may be caused by a belt slipping or a driving motor of insufficient power. This will cause the wheel to slow down when grinding starts. The operator may apply greater pressure on the workpiece against the wheel and increase the stresses in the wheel. Flat spots will tend to develop and cause ‘bumping’ and breakage of the wheel.

Stopping devices

Means for starting and stopping grinding machines should be clearly visible and marked, placed in a safe position and within easy reach of the operator. On portable machines the control should be located so that there is no risk of accidental starting when the grinder is placed on a flat surface.

Mounting of abrasive wheels

The danger of an abrasive wheel bursting is considerably increased if it is not properly mounted; many accidents could be prevented if the people mounting the wheels were instructed in the hazards arising from incorrect mounting and in the correct method of assembly. Paragraphs 46–90 explain the purpose of the various components used with abrasive wheels and the precautions which should be taken in the mounting of each type of wheel.

Figure 6 Basic types of mounting

The major stresses produced in an abrasive wheel under operating conditions tend to become greatest near the hole. It is therefore important that stresses due to mounting and driving are as far from the hole as practicable. This is done by recessing the side of the flange next to the wheel. In the case of straight adaptor and hubbed flanges there is an undercut in place of a recess . With certain exceptions, every abrasive wheel should be mounted between flanges which are at least one third of the diameter of the wheel.

The exceptions are:

(a) mounted wheels and points;
(b) wheels with threaded inserts;
(c) abrasive discs (inserted nut discs and cylinders);
(d) plate-mounted wheels;
(e) cylinder and cup wheels and segments mounted in chucks;
(f) wheels of 20 mm diameter or less.

Recess and undercut

Flanges should be recessed on the side next to the wheel. An exception is the single flat flanges used with threaded-hole wheels. Flanges for wheels with large holes, adapter and rubbed flanges are illustrated in Figure 6. These are not recessed, but the corners of the wheel seating should be undercut so that there will be no bearing on the side of the wheels within 6 mm of the hole.

Uniformity of diameter

As a general rule both the flanges used to secure a wheel to the spindle should be the same diameter and have the same recess diameter to create equal bearing surfaces on the wheel, but the shape of some wheels may not allow this rule to be followed, for example certain internal and cup wheels

Blotters

Blotters of compressible material (usually cardboard not less than

0.2 mm thick and not more than 1.0 mm) as supplied by the wheel or machine manufacturer, should be used between the wheels and their flanges, except for the wheels mentioned in paragraph 56. The main purpose of blotters is to distribute the clamping force of the flanges evenly on the wheel, but they also prevent slipping at lower clamping forces and reduce wear on flanges. Blotters should be an easy fit on the spindle or on the wheel locating spigot, if there is one, and should be slightly larger than the flanges. Care should be taken to see that each blotter is free from wrinkles. If the wheel has been used previously, any pieces of old blotter or loose grains of abrasive should be carefully removed, otherwise high spots will occur leading to severe local stresses when the wheel is clamped tight. A blotter can serve as a label; however, a label cannot act as a blotter.           Figure-7

Blotters should not used with the following types of wheels:

(a) mounted wheels and points;
(b) abrasive discs (inserted nut discs and cylinders);
(c) plate-mounted wheels;
(d) cylinder wheels mounted in chucks;
(e) rubber-bonded cutting-off wheels 0.5 mm or less in thickness;
(f) taper-sided wheels;
(g) wheels with threaded inserts.

Wheel bushes

Bushes are inserts made of plastics or metal and used to reduce the hole size in an abrasive wheel so that it can be mounted correctly on a small diameter spindle. Bushes are hand-pressed into the hole of the wheel and are not recommended for use with wheels fitted to portable grinding machines. They should be slightly less than the width of the wheel and blotters. As the power required to drive a grinding wheel is transmitted to it through the flanges, care should be taken to ensure that the bearing area of the flange is in contact with the wheel and not the bush.

Before using wheel bushes, the depth of the recess in the securing flanges should be measuredto see if it is possible for the bush to slide out of the wheel and become loose in the recess of the flange. This is most likely to occur when two narrow bushes are used one at each end of the hole as an alternative to one bush extending the full width of the wheel. If the depth of the recess will allow this to happen, the bushes should not be used and a wheel with a hole to suit the machine spindle should be used.

Starting new wheels

Before the wheel is run, the guard should be properly adjusted and secured. If the machine is fitted with a work rest, it should be adjusted as close as possible to the wheel and the wheel should then be rotated by hand to ensure that it is clear all the way round. New or re-fitted wheels should be run free at full operational speed for a short period before they are used, and during the trial run everyone shoud stand clear. With portable machines the operator should ensure the machine is operated with the guards properly positioned.

Plain wheels with small holes

Figure 8 shows a wheel correctly mounted. The wheel is gripped between two flanges of equal diameter, the inner (driving) flange being keyed on the spindle and the outer one tightened by a nut on the threaded spindle end. Excessive tightening of this nut is unnecessary and, by setting up an undue crushing stress in the wheel, might cause breakage. Each flange has an equal recess and the blotters are slightly larger than the diameter of the flanges.
Figure 9 shows a wheel incorrectly mounted. Here the flanges are not recessed and blotters are not used. The result may be that when the nut is tightened, proper gripping is not obtained even with normal pressure and localised stresses are set up near the hole. Other unsatisfactory and dangerous conditions which are sometimes found include: flanges unmatched in outside diameter and diameter of recess; one flange omitted and the nut tightened directly against the wheel; use of an ordinary washer as a substitute for a properly recessed flange. Such conditions increase the liability of a wheel to fracture because they result in undue concentration of stress near the hole.

  Figure-8                                                                                   Figure-9

Guards

Purpose of guards

In spite of the care exercised by abrasive wheel manufacturers in the design, manufacture and testing of wheels, the risk of a burst is inherent in every abrasive wheel and a guard of adequate strength must be provided to prevent injury from flying fragments.

A guard has two main functions: firstly to contain the wheel parts in the event of a burst; and secondly to prevent, as far as possible, the operator from coming into contact with the wheel. A guard also has the secondary functions of protecting the wheels against inadvertent damage and preventing an oversize wheel from being fitted.

Internal grinding wheels are, while operating, guarded by the workpiece itself. On fixed internal grinding machines, however, arrangements can be made so that a guard may be placed in position automatically when the wheel in motion is withdrawn from the work (Figures 10 and 11).

Figure 10 A spring-loaded telescopic guard for use on an internal grinding machine. As the workpiece advances towards the wheel the bracket strikes the lugs and retracts the guard to expose the wheel. When the work is withdrawn, the guard is returned by the spring to its original position covering the wheel.

  Figure-10

The internal grinding machine in Figure 11 is enclosed to control the emission of noise, vapour and splash. The sliding door is interlocked to ensure that access to the workpiece is prevented until it has stopped rotating. The abrasive wheel is guarded by a pneumatically operated telescopic guard which retracts and extends like the mechanical guard shown in Figure 10. The valves controlling the movement of the air cylinder are operated by a cam attached to the traversing table. Figure 11 shows the guard retracted to expose the wheel while shows the guard fully extended to cover the wheel.

Figure 11

Another example of guard design can be seen in Figure 12 where an energy absorbent foam lining is contained inside a light sheet-metal housing. This combination can, in some circumstances, be as effective as a heavier all-metal guard. Guards of this kind should only be used after extensive tests involving the bursting of an abrasive wheel have been conducted in safe conditions.       (Figure-12)

The aim is to enclose the wheel to the greatest possible extent, and to keep the opening as small as possible, consistent with the nature of the work. To compensate for the increased exposure caused by wheel wear, either an adjustable vizor is provided (Figure 13) or the guard is constructed so that it can be adjusted manually as the wheel wears down. The guard has side members to limit the exposed area of the wheel and to contain flying fragments. It is usually necessary to construct the outer side member with a hollow boss which will enclose the projecting spindle and nut. When aguard is constructed from several component parts, the fastening should be strong enough toprevent disintegration of the guard in the event of a burst and the dangerous projection of the various parts into the surrounding working area.                              

(Figure-13)

The entire assembly should be securely anchored to the machine frame. Accidents have occurred when guards, though robust, have been attached to the frame by bolts of inadequate strength, with the result that a burst wheel has projected the entire guard bodily from the machine.

Figure 14 Wheel enclosure

angles for various fixed machines (the dotted line\ indicates an alternative guard profile)

(a) Bench and pedestal grinder
(b) Cylindrical grinder
(c) Stationary cutting-off and peripheral surface grinder
(d) Swing frame and highpressure grinder

Figure 14

To protect against this hazard it is advisable to provide substantial steel plates high enough around the table to contain any flying components. In some industries, such as the stone industry, where large wheels may be used with a long horizontal traverse between the wheel and the work, some additional enclosure, other than ordinary wheel guards, is desirable around the machine to restrict the exposure of the wheel below the guard to a minimum.

Wheel guards for portable machines

Guards for portable machines should be so designed that in the event of a wheel bursting / breaking, the guard remains attached to the machine (see Figure 15). The design and construction of the clamp should allow the guard to be positioned directly between the wheel and the operator. The clearance between the inside of the guard and the periphery of an unused wheel should not be greater than 6 mm.

Figure 15

Alternative types of guards for reinforced depressed-centre cutting-off wheels and reinforced straight sided wheels other than cutting-off wheels over 130 mm used on portable machines

Wheel enclosure angles for portable machines

Reinforced depressed-centre, cutting-off wheels and reinforced straight-sided wheels other than cutting-off wheels. (Figures 16 and 17)

A guard for these wheels should have a minimum enclosure of 175 deg. and the side towards the machine should be covered by the guard. When the machine is in use the guard should always be positioned between the operator and the wheel. If the wheel is larger than 130 mm diameter the guard should have a front lip of at least 5 mm or a curtain segment with a minimum height of one quarter of the diameter of the wheel.

Non-reinforced straight-sided wheels (Figure 33)

At least 175o of the abrasive wheel periphery, and both sides, should be covered by the guard. The front curtain should be designed to facilitate easy replacement of the wheel.
Cup wheels (Figure 34)

These should be provided with an adjustable guard which covers the periphery and back of the wheel. The guard should be adjustable to compensate for wear of the wheel and to restrict the wheel exposure to a minimum.

                                  Figures 16                                              Figures 17

Figure 16 A wheel guard for use with a non-reinforced straight-sided wheel on a portable machine

Figure 17 An adjustable band-type guard for straight and taper cup wheels mounted on a portable machine.

Portable and hand-held

grinding machines

The largest number of abrasive wheels used are those found on hand-held machines. These machines are often used by people who have a wide range of skills, from the domestic user to the skilled tradesman, with the predominant user being semi-skilled. Only organic-bonded wheels should be used. Those intended for cutting-off operations should additionally have some form of reinforcement, usually fiber glass. The only exception is for the use of vitrified mounted wheels and points (see Figure 5, page 13, for wheel shapes).

The general safety precautions for abrasive wheels apply equally to all wheels used on all classes of portable machine. It is important that all machine guards are secured in place and are adjusted so that the guard is between the user and the rotating wheels. Serious, often fatal, accidents have happened when a guard is removed to allow an oversize wheel to be mounted on a machine. The unguarded wheel will  be running at a speed in excess of the wheel manufacturer’s recommended maximum with the consequent risk of a wheel burst.

Electric grinding machines

These are the most common machines on which abrasive wheels are mounted. Electrical safety must be considered as well as the safe use of the wheel.

These tools are classified according to the way in which protection against electric shock is provided. For Class I tools, accessible metalwork has to be effectively earthed so as to provide protection for the operator if the metalwork is made ‘live’ because of an internal fault. For Class II tools, marked with the symbol , protection is provided by the use of all insulated or double insulated construction, and accessible metalwork should not be earthed.

Cables and connectors

Hand-held tools are often required to withstand constant handling and rough usage, and the conditions of use should be taken into account when selecting flexible cables for the tools. Cables manufactured to British Standard 6500: 2000 Electrical cables,11 with an abrasion-resistant sheath would satisfactory for normal use,but where the cable is vulnerable to damage,additional precautions such as heavy-duty sheathing or protective braiding will be necessary.

In the case of single-phase tools, two-core cable is suitable for Class II tools, but for Class I tools, a three-core cable is essential. The cable should be connected to the supply by a properly constructed connector, such as a plug and socket. For Class I tools the connector should incorporate an effective means of maintaining earth continuity, for example an earth pin or a scraping earth (ie a sliding connection between the earthed metalwork on the plug and the earthed metalwork on the socket).

Inspection and maintenance:

Routine checks, regular inspection and preventive maintenance are essential if accidents are to be avoided. An efficient maintenance system will also reduce days lost due to tools being out of commission.

The user of a hand-held tool should carry out a visual check on the tool before using it so that obvious defects can be identified, for example damage to the cable sheath, loose plug connections etc. Any tool in an serviceable or unsafe condition must be withdrawn from use until defects have been rectified by a person competent to carry out this class of work.

Routine visual checks are in addition to and are not a substitute for planned maintenance of hand-held tools.

All tools should be accompanied by specific instructions from the manufacturer. If there are no instructions, the following system of planned maintenance is recommended. All hand-held apparatus, including extension leads, should be identified by a serial number which should be recorded in a register. The register should indicate how often each item should be recalled for inspection. The recommended frequency of checks, inspection and testing for portable electric grinders is:

(a) For 110-volt machines the user is to carry out:

(i) a weekly safety check;
(ii) a formal visual inspection (eg a detailed inspection by a person competent to do so);
(iii) a combined inspection and test every three months (eg a detailed inspection and tests by a person competent to do so).

(b) For 240-volt machines the user is to carry out:

(i) a daily safety check;
(ii) a formal visual inspection every week (eg a detailed inspection by a person competent to do so);
(iii) combined inspection and tests before first-time use and then every month (eg a detailed inspection and tests by a person competent to do so).

Operation of abrasive wheels

Truing and dressing

The operator’s fingers may become trapped between the work-rest and the wheel, or the work piece being trapped in a similar way. Although such accidents are more frequently caused by poor adjustment of the work rest, their possibility is minimized by frequent truing to keep the wheel concentric on its spindle. A wheel ‘out-of-round’ will cause excessive vibration and periodic knocking of the work against the wheel. This will invariably result in damage to the abrasive wheel surface, such as ‘loading’ or ‘glazing’, which impair the cutting action and may induce the operator to compensate by additional pressure of the work piece on the abrasive wheel. Dressing the wheel is therefore essential for efficient production, and frequent light dressings are generally preferable to occasional severe dressings. The following important precautions should be taken:

(a) hand dressers should be properly supported so that leverage may be applied without undue effort;

(b) with a dresser of the revolving cutter type, the lugs provided as an anchor should always be used (Figure 13);

(c) haphazard methods of dressing, such as the use of a chipping hammer, or even striking the work against the wheel, should be forbidden;

(d) care should be taken to prevent the possibility of dressing tools becoming jammed between the abrasive wheel and work rest or any fixed part of the machine;

(e) it is important that the work rest is in good condition before wheel dressing and it is helpful to fit a spare rest with a straight edge especially for this purpose.

There are many types of abrasive wheel dressers, and various methods by which these operations may be carried out. If necessary, wheel and machine manufacturers should be consulted on the technical aspects of the subject.

Wheel balance

Abrasive wheels are balanced by the manufacturers within normal limits but after they have been taken into use, wheels used for off-hand grinding can become out of balance if they are not frequently trued. If the out-of-balance force is allowed to become excessive, it may result in damage to the wheel and spindle. For precision grinding, closer limits of balance may be required and this is obtained by various methods such as the use of heavy paint or by an arrangement of sliding weights which are incorporated in the flanges or collet. Adjustment of the sliding weights is normally done with the wheel assembly removed from the machine, on a balancing arbor and stand. An accelerometer probe is placed in contact with a fixed part of the machine near the wheel and a measure of the out-of-balance force is then shown on a meter.

Side grinding

Grinding on the side of a straight-sided wheel used for off-hand grinding is dangerous, particularly when it is appreciably worn or when sudden pressure is applied. However, for certain precision grinding operations it may be necessary to allow the side of the wheel to lightly touch a face adjoining the surface being ground, for example the thrust face on a stepped shaft, and in this case the side of the wheel may be lightly dressed with a diamond to create a shallow relief. Excessive dressing could however create a dangerously weak section which may cause the wheel to break under side loading or due to centrifugal force.

Personal protective equipment

To comply with the Personal Protective Equipment Regulations 199217 and other regulations, for example the Control of Substances Hazardous to Health Regulations18 and the Control of Noise at Work Regulations 2005,19 appropriate protection must be worn. People who use abrasive wheels on any type of machine are exposed to a number of risks:

(a) Injury to the eyes from flying abrasive and metallic particles,

(b) Inhalation of dust from dry grinding operations (for example petrol-engines cutting-off machines);

(c) Physical injury due to flying wheel fragments or ejected work pieces;

(d) Noise and vibration;

(e) On construction sites there will be a need for head protection as well as for feet and hands in addition to the other precautions mentioned.

Eye protection should conform to the relevant BS EN standard such as BS EN 166 Personal eye protection. Specifications;20 BS EN 167 Personal eye protection. Optical test methods;21 and BS EN 168 Personal eye protection.

Dust protection (face masks) etc should comply with BS EN 149 Respiratory protective devices.

Loose clothing Loose clothing such as ties or coat sleeves are easily drawn in between the wheel and the work piece and should not be worn. Rags and waste should not be used near a revolving wheel as they may also become entangled.

Supervision Frequent checks should be made by management to ensure that the safety precautions.

Training- Abrasive wheel grinder

Test – Ring test for Abrasive grinder wheel

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abrasive-wheel-guidelines

Dos and Don ts – Abrasive wheel

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Dos & Don’t Abrasive Wheel

Dos & Don’t s – Abrasive wheel

• DO always HANDLE and STORE wheels in a CAREFUL manner.

• DO VISUALLY INSPECT all wheels before mounting for possible damage.

• DO CHECK MACHINE SPEED against the established maximum safe operating speed marked on the wheel.

• DO CHECK MOUNTING FLANGES for equal and correct diameter. Should be at least 1/3 diameter of the wheel and relieved around hole.

• DO USE MOUNTING BLOTTERS supplied with wheels.

• DO be sure WORK REST is properly adjusted. Center of the wheel or above; no more than 1/8″ away from the wheel.

• DO always USE A SAFETY GUARD covering at least one half of the grinding wheel.

• DO allow NEWLY MOUNTED WHEELS to run at operating speed, with guard in place, for at least one minute before grinding.

• DO always WEAR SAFETY GLASSES or some type of eye protection when grinding.

• DO TURN OFF COOLANT before stopping wheel to avoid creating an out-of-balancing condition.

• DON’T use a cracked wheel or one that HAS BEEN DROPPED or has become damaged.

• DON’T FORCE a wheel onto the machine OR ALTER the size of the mounting hole – if the wheel won’t fit the machine, get one that will.

• DON’T ever EXCEED MAXIMUM OPERATING SPEED established for the wheel.

• DON’T use mounting flanges on which the bearing surfaces are NOT CLEAN, FLAT AND FREE OF BURRS.

• DON’T TIGHTEN the mounting nut EXCESSIVELY.

• DON’T grind on the SIDE OF THE WHEEL, unless wheel is specifically designed for that purpose.

• DON’T start the machine until the WHEEL GUARD is in PLACE.

• DON’T JAM work into the wheel.

• DON’T STAND DIRECTLY IN FRONT of a grinding wheel whenever a grinder is started.

• DON’T FORCE GRINDING so that motor slows noticeably or work gets hot.

• DON’T grind material for which the WHEEL IS NOT DESIGNED.