section 4: machine, guards and tool safety · protection whenever available. pull-back long hair,...

UC System - Shop Safety Reference Manual Section 4 – Machine and Tool Safety 1 June 2013

Machinery Safety Guidelines 1. Get trained before using machines. 2. Follow instruction manuals, operating

instructions, JSAs and other safe operating guidelines whenever using shop equipment.

3. If you don’t know about safe machine use, ask for guidance and training from the shop manager / supervisor.

4. Select the appropriate machines and tools for the job.

5. Do not use equipment in a way that it was not designed or intended to be used.

6. Remove all jewelry from hands, face and neck, and tie back loose clothing and hair that could become entangled in equipment.

7. Always wear required PPE and ensure equipment guards are in place and used.

8. Set up machinery before starting to conduct machine-work. Change dull blades, clamp the materials to be worked, secure drills and tool-bits in machine-chucks, and remove chuck keys.

9. Make sure operating controls are clearly labeled, are easy to reach and you understand each of their functions. Adjust your working location if needed to improve safety and/or gain safer access to machine-controls.

10. Turn off machinery when unattended.

Section 4: Machine, Guards and Tool Safety

OVERVIEW

Drill presses, table saws, band saws, grinders, milling machines, and a variety of hand and small power tools are used in many campus shops. This section presents safety procedures and guidelines for machine-tool use, use of guards and personal protective equipment (PPE), and information about machinery repair and routine maintenance.

SAFE WORK PRACTICES

Safe work practices in shops are critical to preventing work-related injuries. Safety must become second nature to you. Crushed hands and arms, severed fingers, and blindness can occur when shop work is done carelessly. Machine parts, functions, or processes that may cause injury must always be controlled, guarded, or eliminated if possible. And, awareness of other’s work ongoing nearby is critical to maintaining your own safety and health. Ask the shop Manger/Supervisor for training if you do not know how to use a machine or a power tool, and never use machinery or power tools without having been properly trained. Your health and safety depends upon your personal actions, knowledge and safe use of potentially very dangerous shop equipment. Stay alert when working, and keep others at a safe distance when


using a machine. Stay away from others using shop machinery and don’t interrupt them in the middle of detailed machine-work. Wait to engage them until they can safely divert their attention from their machine work to you. If you see a fellow shop-user having difficulty working (e.g., from being over-medicated, ill, agitated or excessively tired), let the shop manager/supervisor know so they can address the situation. Everyone’s safety and health are dependent upon each other when working in shops.

L.O.T.O. AND MACHINE GUARDING

Always use lock out / tag out (known as “LOTO”) procedures when inspecting or repairing machines. Immediately report to the shop manager/supervisor any equipment that is unsafe or needs repair, and don’t hesitate to lock out / tag out a piece of defective equipment until it can be repaired or replaced. For more information on lock out / tag out, see that section of the Shop Safety Manual for further guidance. Machine guards must be installed according to current regulatory requirements. Lack of guards on older machines that were not supplied by manufacturers when they were not required cannot be “grand-fathered” under OSHA laws. There are many after-market guards now available and some manufacturers offer after-market guards for their older equipment. In addition, there are many other manufacturers who make guards for older equipment. Older machines may need to be retrofitted with guards to cover unsafe locations where moving, rotating, sliding, gliding, rolling or other machine-components may come in contact with the user to comply with current machine-guarding codes. UC Berkeley has a written “Machine Guarding Program” that details the requirements for machine guarding including locations and types of guards available for shop equipment at the following link: http://ehs.berkeley.edu/hs/455-machine-guarding-program.html It will help you identify locations on your equipment that may need guarding. If you suspect your equipment needs to be guarded, please consult with the shop manager / supervisor about your concerns, and the possible locations needing machine guarding. Do not operate equipment with guards missing, and work with the shop manager / supervisor to identify, improve and/or install new or missing guards at locations where they are needed. For questions about safe use of any shop equipment, consult the UC Berkeley Job Safety Analysis online library (JSA Library) at the following link: http://ehs.berkeley.edu/hs/62-job-safety-analysis-jsa-library/106-jsa-by-topic.html#shpsaf . The JSA Library is a reference source for shop safety best practices and available for everyone’s use. If you have JSAs you’d like to contribute to the library, please send them to the “contact us” link on the UC Berkeley EH&S Dept. website (www.ehs.berkeley.edu).

http://ehs.berkeley.edu/hs/455-machine-guarding-program.html

http://ehs.berkeley.edu/hs/62-job-safety-analysis-jsa-library/106-jsa-by-topic.html#shpsaf

http://ehs.berkeley.edu/hs/62-job-safety-analysis-jsa-library/106-jsa-by-topic.html#shpsaf

http://www.ehs.berkeley.edu/


DRILL PRESS

A drill press is used to drill holes of various sizes in wood, metal, and other materials. Usually mounted or bolted to the floor or work bench, it consists of a base, column, table, rotating spindle with attached drill-chuck, which is usually driven by an electric motor. The spindle and drill-chuck has a feed lever, or set of turning handles, that move the spindle and chuck vertically downward to drill the hole in the material placed on the table. The spindle and chuck are “at rest” in the “up” position. The table can also be adjusted vertically, and on some drill presses horizontally, and is usually moved up/down by a rack and pinion. The table is held in place by a clamp on the column. See Figure 4.1. Figure 4.1 – Drill Press

Drill Press Use and Safeguards UC policies and State regulations require all that all moving parts be guarded at all times, that the drill press be bolted or clamped to the floor or bench, and be in good working condition.

Guards are required for all rotating and moving parts such as the point of operation where the material is being drilled, all the power transmission components, and at all other moving parts of the machine not directly in control of the operator (e.g. the feed handle cannot be guarded but is controlled by the operator). The adjustable debris guard (photo at left) must always be set in place before attempting any type of drilling work.

Drilling Depth Stop


Drill Press Training You must receive specific training and wear PPE before working with a drill press. Training must be documented and include instruction from an experienced user on how to operate a drill press, review of this section of the Shop Safety Manual and/or a Job Safety Analysis (JSA) or Standard Operating Procedure (SOP) for a drill press, and the proper use of guards and PPE for the specific press you are using.

Required PPE At a minimum, you must always wear safety glasses when operating a drill press. Face shields are recommended for added protection whenever available. Pull-back long hair, or restrain your hair under a hair-net.

Drill Press Safety Tips

1. Select round, hex, or triangular shank drill-bits. 2. Secure the drill-bit in the chuck and remove the chuck-key before turning

on the machine. 3. Work at a drilling-speed appropriate for the drill-bit size and material. In

general, a larger diameter equals a slower speed, and in general, faster feeding or rotation speed is not always better!

4. Position the work to avoid drilling into the table. Set up your work with a “sacrificial” piece of wood or other material underneath the work to prevent drilling the table if through-drilling a hole in your work.

5. Clamp the work to the table. Never hold the work piece by hand. 6. Always clamp sheet metal to table before drilling. 7. Feed the drill-bit evenly into the work piece letting the drill cut through the

work and not forcing it. If you see smoke or hear high-pitched squealing, stop feeding as you may be feeding too fast, your drill-bit may be dull and need replacing, or you may need to add a little lubricant to the drill-bit.

8. Back out of deep holes several times during drilling to allow cut-material to exit the hole and to dissipate heat.

9. After turning off the drill-press, clear off chips with a soft-bristle brush or shop-vac (don’t use your fingers or hands(!)).

10. Tidy the machine and leave it ready for next use when you are finished drilling your hole(s).


TABLE SAW

A table saw consists of a circular saw blade that is driven by an electric motor. The blade protrudes through the surface of a table, which provides support for the material being cut. The height of the blade determines the depth of the cut that is made in the material, and the angle of the cut is controlled by adjusting the tilt-angle of the blade. See Figure 4.2.

Figure 4.2 Table Saw

Table Saw Use and Safeguards All table saws used in UC shops must be in good operating condition and be securely mounted to floor or bench-top. All rotating or moving parts must be guarded. Portions of the saw that extend beyond or behind a table must be covered with a guard, such as a crown guard (photo above and below), or with an exhaust hood if an exhaust system is required. Anti-kickback devices, hood guards, and spreaders are required. Push sticks and/or push shoes are highly recommended to keep hands away from blades. All moving parts (belts and gears) and the point of operation (where the cut is being made) must be guarded. Table saws must have a crown guard that completely covers the blade projecting above the table. The guard must ride the thickness of the stock

Push Stick

Crown Guard


Table Saw Safety Tips

1. Set blade height a maximum of ¼” (6mm) above the stock thickness. This ensures that if your hand slips, you will get a slight cut rather than lose a limb.

2. Position the guide fence and T-Mitre as may be needed by the cut. 3. Make sure the tabletop is smooth and polished. Dirty, rough tables require extra force to

push the stock through the blade. This can increase your chance of slipping or losing your balance.

4. Make sure the blade is sharp and in good condition. A dull blade can cause you to push harder than needed and possibly lead to injury if your hand(s) should slip. Also, dull blades cause burning of the stock.

5. Stand balanced and avoid awkward movements to prevent falling into the blade. 6. Select seasoned, dry, flat wood for cutting. 7. Remove any nails, screws, stones, etc. from the stock and check for knots, as these

items can become projectiles and cause injury, as well as ruin the blade. 8. Release the stock only after it has gone past the blade, and wait for the blade to stop

before removing the cut-stock from the table. 9. Use a push stick to cut stock that is less than 6” (150 mm) wide. 10. Make sure that the blade has stopped turning before you adjust the table. 11. Do not leave or clean the saw until the blade has come to a complete stop. 12. Clean off saw dust with a soft-bristle brush or a shop-vacuum (don’t use your fingers or

hands(!)).

13. Tidy the table saw and leave it ready for next use when you are finished.

being cut, adjusting to the thickness of the stock automatically as the stock is fed through the saw. Always keep the blades' guards, spreaders, and anti-kickback devices in place. Align the spreader with the blade. Check their action to make sure they operate properly before cutting.

Table Saw Training You must receive specific training and wear personal protective equipment (PPE) before and when working with a table saw. Training must be documented and include instruction from an experienced user, preferably the shop manager / supervisor, on how to operate a table saw, review of this section of the Shop Safety Manual and/or a JSA or SOP for a table saw, and the proper use of guards and PPE for the specific saw you are using. You must be qualified and authorized by the shop manager / supervisor before using a table saw in their shop.

Required PPE You must wear safety glasses, goggles, or face shields when operating a table saw. If the cutting operation is dusty, wear a dust mask. Do not wear gloves, neck-ties, dangling jewelry, loose long sleeves, or any other loose fitting clothing that could get caught in the blade. Non-slip footwear is also highly recommended. Tie back long hair.


Figure 4.3 – Vertical Band Saw

Figure 4.4 – Horizontal Band Saw

Figure 4.5 – Cutting a Curve on a Vertical Band Saw

BAND SAW

Band saws have blades comprised of continuous steel bands with teeth along one edge and are used to cut a variety of materials including wood, plastic and metal. There are different kinds of blades designed to cut different kinds of materials. The steel band cutting blade is powered by an electric motor, and runs on two large wheels rotating in the same plane which draws the blade across the material being cut continuously. The material being cut is located between the two large wheels. There are two orientations of band saws: Vertical (Figure 4.3) and Hinged-horizontal (Figure 4.4). On vertical machines work-pieces are fed into the cutting blade usually by hand. On hinged-horizontal band saws, the blade is usually drawn through the material by the weight of the saw frame applying uniform pressure. Regardless of orientation, band sawing produces uniform cutting as a result of an evenly distributed tooth load and generally even pushing force. Band saws are used to produce straight cuts (mostly on the hinged-horizontal saw), but are particularly useful for cutting irregular or curved shapes on the vertical saw as shown in Figure 4.5.


Band Saw Use and Safeguards All vertical band saws must be bolted to the floor or bench. Horizontal band saws may be bolted to the floor, or may be designed to roll on wheels, but must have a means to secure the saw to the floor once placed in the cutting location. All band saws must have blade tension control devices with indicators.

As with other machinery, all moving parts and the point of operation (where the cut is being made) must be guarded. The entire saw blade must be enclosed or guarded, except for the working portion of the blade between the bottom of the guide rolls and the table. While gaps in the guards of ¼” or less are allowed, adjust the blade guard height as close as possible to the table without interfering with movement of the stock.

Push sticks (photo at right) or push shoes are recommended to keep fingers and hands away from moving blades.

Band Saw Training You must receive specific training and wear personal protective equipment (PPE) before working with a band saw. Training must be documented and include instruction from an experienced user on how to operate a band saw, review of this section of the Shop Safety Manual and/or a JSA or SOP for a band saw, and the proper use of guards and PPE for the specific band saw you are using.

Required PPE Operators must wear safety glasses. If the material being sawed chips severely, use a face shield in addition to safety glasses. Non-slip footwear is also highly recommended. As with any power saw, do not wear gloves, neck-ties, dangling jewelry, loose-fitting long sleeves or other loose fitting clothing that could be drawn into the saw blade or rotating parts. Tie back or cover loose hair.


Band Saw Safety Tips

1. Clear tools, debris, and unnecessary materials off saw table. 2. Verify location of on/off switch and emergency power disconnect. 3. Check blade for tightness and tension as needed. 4. Adjust the blade guard as close as possible to the table without interfering with

movement of the stock. A maximum of ¼” gap is allowed by law. 5. Adjust the travel guard so that the blade will travel within the angle or channel of the

guide system. 6. Operate the saw at manufacturer’s recommended speed. 7. Cut only those materials recommended for use with the particular blade. Change the

blade as needed to only use the blade intended for the material being cut. 8. Do not force material into the blade. Allow the blade to remove the material at a

steady rate and feed the material towards the blade with minimal effort. If the blade is dull, do not push harder…. Change the blade!

9. Unplug power cord, or lock the disconnect switch in the “off” position, before changing a blade or servicing the saw.

10. Test the saw after disconnecting power to ensure power is “off” and before beginning service.

WOOD PLANER / WOOD JOINTER

WOOD ROUTER

Wood Planers, Wood Jointers and Wood Routers are used to machine intricate angles, curves, channels and “joints” in wood, particularly along edges, or to remove material-thickness from a piece of wood and/or create a smooth finish on the surface of the wood stock being worked. Wood Planers may be fixed or hand-held and have rotating flat “planing heads” comprised of planing teeth along the entire cylindrical surface of the planing head. There are many different models and designs of wood planers. Hand-held planers have one motor, while large wood planers often have more than one drive motor with a high-speed very powerful motor driving the planing head, and another motor driving the feeding of the wood-stock being planed through the rotating planing head. Wood Jointers have a rotating “jointing bit” that is intricately tooled in the shape desired. They are used to precision-machine the edge of a piece of wood to prepare it for

Wood Planer

Hand-held Wood Planer


making a “joint” in a piece of furniture or other wood. They are also used to create decorative moldings and curves along an edge of a piece of wood. Wood Routers are used to “route” a groove or a square-cut valley or edge along the length of a piece of wood. Some Wood Routers may be hand-held while others are larger and fixed on a stand bolted to the floor. A Wood Jointer can be used as a Wood Router often simply by changing the machine tool used in the tool-chuck of the machine and adjusting the machine for the intended use. Some larger pieces of shop equipment “Wood Planers / Wood Jointers / Wood Routers” are combination pieces of equipment in that they can be set up to do different types of wood-working operations depending upon how the machine is configured by the user.

Wood Planer / Jointer / Router Use and Safeguards There are many different designs and types of Wood Planers / Jointers / Routers. They are potentially very hazardous pieces of equipment so get safe-use training on the safe operation of specific pieces of equipment you intend to use from your supervisor of shop manager. Do not assume that because you have been trained on one make/model of machine that you know how to safely operate another type of machine, or set up a machine for safe operation without specific orientation to your machine. Planer / Jointer / Router heads rotate at very high speed and, on larger pieces of equipment, can “coast” for many minutes when shut-off before coming to a stop. Spinning blades may appear to be a smooth metal surface making you think they have stopped moving when they are still moving and dangerous. Ensure that when stopping a Wood Planer / Jointer / Router, and especially when maintaining or adjusting it, that the planer / jointer / router head has fully stopped before working on the machine. Engage machine-brakes to stop the head from rotating if available. Conduct LOTO on the machine and use a sacrificial wood piece to confirm the rotating head has fully stopped before adjusting the machine or removing a safety guard. All larger Wood Planers / Jointers / Routers must be bolted to the floor or bench. This equipment may be designed to roll on wheels for easy relocation, but must have a means to secure the Planer / Jointer / Router to the floor once placed in the wood-working location.

Wood Planer / Jointer

Wood Router / Jointer


All Wood Planers / Jointers / Routers must have cutting-head guards installed on them that automatically adjust to cover the working-head / wood-cutting blades as the wood-stock is being fed through the machine. For manually-fed machines, push sticks (photo at right) or push shoes are recommended to keep fingers and hands away from moving blades.

Wood planer Training You must receive specific training and wear personal protective equipment (PPE) before working with a Wood Planer / Wood Jointer / Wood Router. Training must be documented and include instruction from an experienced user on how to operate the specific equipment you’ll be using, review of this section of the Shop Safety Manual and/or a JSA or SOP for a Wood Planer / Wood Jointer / Wood Router, and the proper use of guards and PPE for the specific equipment you are using. You must be qualified and authorized by the shop manager / supervisor before using a Wood Planer / Wood Jointer / Wood Router in their shop.

Required PPE Operators must wear safety glasses. If the material being planed / jointed / routed chips severely, use a face shield in addition to safety glasses. Larger thin materials can be noisy when being planed / jointed. Consider using hearing protection if the material you are working creates excessive noise. See “Hearing Conservation Section” of this manual for more information on ear-protection selection / use. Non-slip footwear is also highly recommended. As with any power equipment, do not wear gloves, neck-ties, dangling jewelry, loose-fitting long sleeves or other loose fitting clothing that could be drawn into the tool-head or other rotating parts. Tie back or cover loose hair.


Figure 4.6 – Pedestal Grinder

Wood Planer / Jointer / Router Safety Tips

1. Clear tools, debris, and unnecessary materials off Planer / Jointer / Router table. 2. Verify location of on/off switch and emergency power disconnect. 3. Check tool head for tightness and tension as needed. 4. Adjust the tool head guard as close as possible to the table / guide without interfering

with movement of the stock. A maximum of ¼” gap is allowed by law. 5. Adjust the in-feed and out-feed table height so that the wood-stock will smoothly

travel within the machine guarding of the stock-guide system. 6. Operate the Wood Planer / Jointer / Router at manufacturer’s recommended speed. 7. Plane / Joint / Route only those wood and other materials recommended for use with

the particular head-tool. Change the head-tool as needed when they get dull. 8. Do not force material into the head-tool. Allow the head-tool to remove the material at

a steady rate and feed the material towards the head-tool with minimal effort. If the head-tool is dull, do not push harder…. Change the head tool to a sharper tool!

9. Use machine brakes to ensure the planer-head has fully stopped before adjusting or servicing the equipment.

10. Confirm the tool-head has stopped rotating touching the tool-head with a sacrificial stick before adjusting or servicing the equipment.

11. Unplug the power cord, or lock the disconnect switch in the “off” position, before changing a head tool or servicing the Planer / Jointer / Router.

12. Test the Planer / Jointer / Router after disconnecting power to ensure power is “off” and before beginning service.

PEDESTAL OR BENCH GRINDER

A grinder uses an abrasive stone wheel, wire brush or polishing wheel to grind / polish objects that need to be shaped or repaired. It is often used to remove metal from a work piece, sharpen tools, clean or polish parts. It consists of an electric motor driven wheels and a tool rest used to guide and feed work-pieces onto the wheel. The wheels are usually mounted right onto the motor-shaft which protrudes from both ends of the motor allowing the motor to power two different grinding / polishing wheels. A Pedestal Grinder is simply a Bench Grinder mounted onto a free-standing pedestal. Bench grinders must be bolted securely to the bench-top, Pedestal grinders must be securely bolted to the pedestal, and then the pedestal must be bolted to the floor. It is against the law to operate a grinder without it being bolted to support structure that will securely hold the grinder in place.


Figure 4.7 – Bench Grinder

Figure 4.8 – Bench or Pedestal Grinder Components

Grinders can create lots of hot sparks and hot flying metal debris when grinding iron, steel and some other metals. When mounting a grinder, it must be located in a fire-safe location where any sparks and hot metal particles cannot fall into cracks or become exposed to any material that can burn. Grinders are often located in all-concrete or sheet-metal-lined enclosures for this reason. If grinders use a wire brush for removing paint from surfaces, the paint-chips created by the “wire brushing” process could be toxic and should not be inhaled or ingested. A grinder’s safety-guards and tool rest must be properly set up to ensure safe use. Grinding wheels are generally made of stone and spin very fast. They are highly balanced tools as supplied by the manufacturer. Hitting the stone with a sharp or heavy object can cause microscopic fractures within the grinding stone, or chip off a piece of the stone, unbalancing the stone and causing vibration at high speed. Grinders should run smoothly and quietly when grinding stones, wire brushes or polishing wheels are in good condition. If there is excess vibration DO NOT OPERATE THE GRINDER (!) until the source of vibration has been determined and corrected. Vibration is an indication of degradation of the grinding wheels. Broken / damaged wheels can become sources of shrapnel and projectiles if the wheel fractures during high-speed rotation. Become familiar with the controls and components of your grinder(s) by reviewing Figure 4.8 below.


Grinder Use and Safeguards Set up the grinder in a fire-safe location free of all combustible or flammable materials. All grinders by law must be solidly mounted to floors or benches. The “work rest” or “tool rest” must be adjusted to within ⅛ inch of the grinding wheel. Adjustable tongue guards should be within ¼ inch from the wheel. Side guards must cover the spindle, nut and wheel-mounting-flange, and at least 75% of the wheel. Safety glass eye shields must be routinely cleaned and scratch-free to allow the user to see the wheel. As grinding stones wear due to repeated use, their diameter decreases. You will need to check and adjust the clearances of the tool/work rest and the spark guards to ensure proper set up the grinder for safe use each time you use the grinder. In addition, certain materials must NOT be “ground down” using a grinder unless special grinding wheels are installed on the grinder. For example, trying to grind aluminum or plastic materials on a standard grinding stone will ruin the grinding stone and possibly cause injury due to induced structural instability and vibration in the stone wheel caused by grinding these materials.

Grinder Training You must receive specific training and wear personal protective equipment (PPE) before working with a grinder. Training must be documented and include instruction from an experienced user on how to operate and adjust a grinder, and may include review of this section of the Shop Safety Manual and/or a JSA or SOP for a grinder, as well as the proper use of guards and PPE for the specific grinder style, and types of materials, you are intending upon grinding, brushing or polishing.

Required PPE Grinder users must wear full-face protection, hearing protection, leather gloves, and a leather apron. Leather shoes / boots are also recommended.


Lathe with CNC Control

Chuck and Guard CNC

Chuck Speed Controls

Feed Screw and Carriage

Controls

Tail Stock

Base

Manual Tool Feed Screw and Carriage Controls Tool Holder and Carriage

Lead Screw

Bench and Pedestal Grinder Safety Tips

1. Always stand to the side of the grinder when starting the electric motor in case the grinding

stone is defective or materials stuck to the wheel become projectiles. 2. Use the correct wheel for the material you are grinding, polishing, or buffing. Change the

wheel to suit the material being worked, or if vibration is excessive. 3. Adjust the tool rest as close as possible to the grinding wheel without touching the wheel. It

must have a gap of between 1/16 and ⅛ inches. 4. Keep the face of the abrasive wheel square. Use a dressing tool to remove some of the

abrasive compound to square the wheel. 5. Never grind on the side of the wheel. This can cause the wheel to shatter. 6. Avoid overheating metal (red-when too hot, bluing when cooled) when grinding. If the metal

becomes too hot and is allowed to cool too slowly, it may become soft. If it is cooled too quickly (quenched), it may become brittle.

7. Dip the metal being worked into the water pot attached to the bottom of the grinder as you shape it to keep it from getting too hot.

8. If your grinder does not have a water pot, place a container of water near the grinder to cool the piece you are grinding.

9. When you’ve shut off a grinder, it can take a long time to coast to a stop. Never try and touch a coasting grinding wheel to slow it down. Allow the wheel to stop over time, or use a sacrificial piece of metal to slow the coasting wheel to a stop.

10. Always handle the material being ground when wearing leather gloves for both heat and physical impact protection.

11. Unplug the power cord, or lock the disconnect switch in the “off” position, before changing a grinding wheel or servicing the grinder.

12. Test the grinder after disconnecting power to ensure power is “off” and before beginning service.

LATHES


Bench-top Model Lathe

Large CNC Controlled Engine Lathe

Lathes shape metal, wood and other solid materials and machine them from square or rectangular shaped into “round” materials. The general operation of a lathe is commonly known to shop personnel as “turning”. Lathes are horizontal pieces of equipment where the stock being worked is held by a rotating “chuck” and “turned” around a horizontal axis. A cutting tool mounted on a “tool holder” is brought into contact with the rotating material to cut away material until the desired shape and diameter is achieved. The “tool holder” may be manually fed or motor-driven and is mounted to a “tool carriage” that moves along the horizontal X axis, and possibly the Y axis, of the machine. Some tools carriages may also have adjustment in the vertical “Z” axis as well. Lathes may be manually operated, mechanically automated, or digitally automated via computer numerical control (CNC). The more-automated a lathe is, the more enclosed and guarded the machine must be. Automated lathes follow robotic programming language and are fully computer controlled. As such, they are physically powerful pieces of equipment and can easily entrap or crush someone or a body part if persons were to get caught up in the pathway of an automated lathe while it was executing a work-piece program to fabricate a machine part.

Lathe Use and Safeguards Lathes must be in good condition and properly lubricated for safe use. As with all other machinery, guards are required for all moving parts and the point of operation. Guards of the rotating chuck, the lead screw and possibly other locations on the lathe must be in place before use. An adjustable chip shield must be in place at the point of operation whenever cutting is taking place. So that the chip-shield moves with the tool / point of operation, this guard is usually mounted on the X-Y Axis carriage and moves with the tool carriage’s movement.


Lathe Training You must receive specific training and use personal protective equipment (PPE) before working with a lathe. Training must be documented and include instruction from an experienced user on how to operate the specific lathe you’ll be using and include review of this section of the Shop Safety Manual and/or a JSA or SOP for a lathe, as well as the proper use of guards and PPE for the specific lathe you are using. You must be qualified and authorized by the shop manager / supervisor before using a lathe in their shop.

Required PPE Operators must always wear safety glasses and slip-resistant shoes are highly recommended. Remove all jewelry from face, neck and hands. Never wear loose clothing or other articles that dangle and could catch on the rotating chuck or lead screw. Tie back hair or keep restrained by using hair-nets.

Lathe Safety Tips

1. Keep area around machine clear of debris; wipe up any oil on the floor. 2. Secure any holding devices (e.g., chuck, tool holder, tail stock, etc….). 3. Select the right kind of tool / cutter for the job and material. 4. Check to make sure that the machine is turned off and fully at rest before attaching the work-

stock to the chuck, or when setting up the cutting tool. 5. Make sure that the arbor and collars are clean before mounting them in the tail stock spindle. 6. Handle sharp cutting tools with a rag. 7. Securely set the work piece in the chuck jaws. 8. Remove and set to one side the chuck key. 9. Be certain that the holding location of the work-stock in the chuck clears the tool holder, arbor

and the tool carriage and supports when the chuck is rotating. 10. Select the proper turning speed, rpm, and rate of feed on the lead screw for the job. 11. If possible, disengage the control handles when using automatic feeds. 12. Keep hands away from the revolving chuck, tool holder and point-of-work location at all times. 13. Never touch the metal chips with your fingers. Clear chips away from the cutting tool with a

brush. After cutting is finished, vacuum or sweep debris rather than blowing with an air hose. 14. Release any automatic feeds after the job is complete. 15. Clean and wipe the machine when finished.


Figure 4.9 – Milling Machine with X-Y Axis CNC Control

MILLING MACHINE

Milling machines shape metal and other solid materials. A mill-bit-cutter rotates about the spindle axis milling away material from a work-piece that is affixed to a moveable table. In contrast to drilling, where the drill is moved exclusively along its rotating axis and the work-piece is held fixed, milling involves movement of the rotating mill-cutter in relation to the work-piece which is attached to a multi-axis table that allows movement of the work-piece in all directions. The cutter and work-piece move relative to each other, generating a tool path along which material is removed. Milling machines may be manually operated, mechanically automated, or digitally automated via computer numerical control (CNC). The more-automated a milling machine is, the more enclosed and guarded the machine must be. Automated milling machines follow robotic programming language and are fully computer controlled. As such, they are physically powerful pieces of equipment and can easily entrap or crush someone or a body part if persons were to get caught up in the pathway of an automated milling machine while it was executing a work-piece program to fabricate a machine part. See Figure 4.9 for a photo of a typical manually-operated milling machine with CNC (computer numerically controlled) capability with X and Y axis control on the table, but manual control on the Z axis milling head / tool bit.

Rotating Milling Bit

Work-piece vise

CNC Controlled motors to move X-Y Axis Table

Manual Table Movement Handles

X-Y Axis Table

Milling Motor, Speed Control and Milling Head


Milling Machine Use and Safeguards Milling machines must be in good condition and properly lubricated with all moving chains and gears guarded at all times. As with all other machinery, guards are required for all moving parts and the point of operation. An adjustable chip shield must be in place at the point of operation whenever cutting is taking place. So that the chip-shield moves with the work-piece point of operation, this guard is usually mounted on the X-Y Axis Table and moves with the table’s movement.

Milling Machine Training You must receive specific training and personal protective equipment (PPE) before working with a milling machine. Training must be documented and include instruction from an experienced user on how to operate a milling machine and include review of this section of the Shop Safety Manual and/or a JSA or SOP for a milling machine, as well as the proper use of guards and PPE for the specific milling machine you are using. You must be qualified and authorized by the shop manager / supervisor before using a milling machine in their shop.

Required PPE Operators must always wear safety glasses and slip-resistant shoes are highly recommended. Remove all jewelry from face, neck and hands. Never wear loose clothing or other articles that dangle and could catch on the cutter. Tie back hair or keep restrained by using hair-nets.


Basic Safety Guidelines 1. Keep all tools in good condition with regular

maintenance. 2. Use the right tool for the job. 3. Examine each tool for damage, including the

condition of the power-cord before use. 4. Do not use any tools that damaged, and “red

tag / LOTO” any tool with damaged power cord until it can be repaired.

5. Operate tools according to the manufacturer's instructions.

6. Before you start your work think about what you will be doing and where you’ll be working. Then, select and use the appropriate PPE for any hazards such as dust, fumes, mists, vapors, or gases that may be local to the work, or created by the work you are doing…

Milling Machine Safety Tips 16. Keep area around machine clear of debris; wipe up any oil on the floor. 17. Clean and dry the table before setting up. 18. Secure any holding devices (e.g., vise, angle plate, dividing head, or tail stock). 19. Select the right kind of cutter for the job. 20. Check to make sure that the machine is turned off before inserting the cutter. 21. Make sure that the arbor, cutter, and collars are clean before mounting them in the

spindle. 22. Handle sharp cutters with a rag. 23. Securely set the work piece in the vise with a rubber hammer or mallet. 24. Be certain that the holding device clears the arbor and the over-arm supports. 25. Select the proper cutting speed, rpm, and rate of feed for the job. 26. Disengage the control handles when using automatic feeds. 27. Keep hands away from the revolving cutter at all times. 28. Never touch the metal chips with your fingers. Clear chips away from the cutter with a

brush. After cutting is finished, vacuum or sweep debris rather than blowing with an air hose.

29. Release any automatic feeds after the job is complete. 30. Clean and wipe the machine when finished.

HAND & POWER TOOLS

Shop workers often take hand and power tools for granted since they are used so frequently, and don’t think of the hazards that they may create. It can be easy to forget the potential danger these tools may pose. Nevertheless, many tool-related accidents occur due to improper maintenance or misuse of hand and power tools. Pay close attention to the condition of your tools and know how to use them properly. Before you start your work, think about what you’ll doing, where you’ll be doing it, and what hazards you’ll need to protect yourself from, then plan your safe work and PPE selection accordingly.


Hand Tools Hand tools are manually powered tools such as pliers, screwdrivers, hammers, hand saws, and wrenches. While not powered by an external source, hand tools can be dangerous if improperly handled or used to perform the wrong task. Never use a tool for something other than for what it was intended. Common examples of misuse include using a

wrench for a hammer or using a screwdriver as a chisel or crowbar. Don’t use extender or “cheater” bars to increase leverage or force on wrenches. Keep hand tools in good working condition and always inspect them before use. Dispose of broken or worn-out hand tools.

Hand Tool Safety Tips

1. Keep knife and saw blades sharpened. 2. Direct blades away from your body and other workers in the work area. 3. Replace wrenches when jaws are worn and begin to slip. 4. Replace tools with splintered handles, cracked blades, or any other defect. 5. Use tools for their intended use only.

Hand Held Power Tools

Hand Held Power tools are classified by their power source and include electrical batteries, electrical plug, pneumatic, fuel, hydraulic, and powder actuated tools. Potential hazards include electric shock, injury from moving parts, fires and burns from spark-producing operations, and injury from projectiles “driven” by the design of the tool or “launched” by some unintended tool use . Most power tools are designed with safety in mind. Modern manufacturers must follow Occupational Safety and Health Administration (OSHA) guidelines that require all power tools to have guards, switches and controls, electrical grounding, and maintenance guidelines. These features are important for your safety. Do not use any tools that have broken or missing guards, switches, or grounding conductors. Never remove safety guards.


Power Tools that Require Guards

1. Tools with non-flush projections on revolving or reciprocating edges.

2. Tools with rotating blades, bits, discs or cutters. 3. Tools with reciprocating blades. 4. Tools with sanding and grinding parts.

Older powered hand tools may not have modern safety features and guards “designed into” the equipment. They may not be reviewed and listed by an independent testing lab such as UL or ETL who have reviewed the design and manufacture of equipment and determined it meets or exceeds modern safe design standards. If you have older powered hand tools with parts of the tool that should be guarded missing or that never had a guard, consider replacing these powered hand tools with new, fully guarded and modern electrically protected equipment.

Required PPE When Using Hand-Held Power Tools Operators must always wear safety glasses when operating any hand-held power tool. Slip-resistant shoes are highly recommended. Remove all jewelry from face, neck and hands. Never wear loose clothing or other articles that dangle and could catch on the rotating power tool. Tie back hair or keep it restrained by using hair-nets or tucking it into your shirt collar.

Electrical Tools Electrical power tools include power drills, power saws, power grinders, etc.. Electrical tools introduce the risk of shock, which can potentially lead to heart attacks or serious burns. To help avoid electrical shock, it is required that all exposed non-current carrying metal parts of tools that may become energized be grounded with a 3-wire plug. In addition, to ensure your power tool is properly manufactured, look for a UL label or ETL label on the power tool name plate. This will tell you that an independent test-lab has looked at the design and manufacture of the power tool, and that it meets current best practice in electrical safety design.


Safety Guidelines for Electrical Tools

1. Inspect cords for defects such as cracks, frays, and other signs of wear or faults in the cord insulation. Remove from service and red-tag any power tool with a defective power cord.

2. Use properly grounded tools with three-prong plugs and double insulation. 3. Inspect the plug for cracks and for missing, loose, or faulty prongs. 4. Use manufacturer recommended / provided guards and shields. 5. Switch off tools before connecting them to a power supply. 6. Disconnect the power supply before making adjustments or changing accessories such as a

drill bit or saw blade.

7. During use, keep power cords clear of tools and away from the path that the tool will take. 8. Use approved extension cords that have the proper wire size (gauge) for the length of cord

and power requirements of the electric tool that you are using. 9. Use appropriate PPE for the work you are doing. This may include items such as safety

glasses or goggles, hearing protection, dust mask, gloves, safety boots or shoes, or rubber boots.

Pneumatic Tools

Pneumatic tools are powered by compressed air. Common types of these air-powered hand tools include nail guns, stapling guns, grinders, drills, riveting guns, and jackhammers. These tools can cause injuries due to flying parts or loose attachments. Before you begin a job, make sure that pneumatic tools are fastened securely to their air hoses to prevent them from becoming disconnected while in use.

Safety Guidelines for Pneumatic Tools

1. Review the manufacturer's instructions before using a tool. 2. Wear safety glasses or a face shield and, where necessary, safety shoes or boots and hearing

protection. 3. Make sure air hoses do not present a tripping hazard. 4. Never point a compressed air gun at another person. 5. Use the recommended air pressure for the task. 6. 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. 7. 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. 8. Keep tools clean and lubricated, and maintain them according to the manufacturers'

instructions. 9. Do not attempt to catch falling machinery or power tools. 10. Support heavy tools with a counter-balance when possible. 11. Always disconnect the air-tool from the air supply before reloading the tool with nails, new sand

paper, etc., trouble shooting or repairing the pneumatic tool.


Safety Guidelines for Hydraulic Tools

1. Never exceed the load limit marked on the tool. 2. Always use a hydraulic jack on a firm and level surface. 3. Inspect all hydraulic tools at least once every six months 4. Inspect all jacks used outside the shop before they go out and when they return. 5. Immediately inspect any hydraulic tool when subjected to an abnormal load, pressure,

or shock. 6. Always use leather gloves, safety shoes, and face, eye and ear protection. 7. It’s recommended to use impact-resistant / vibration damping gloves.

Liquid Fuel Tools Liquid fuel-powered tools are usually powered by gasoline. Examples of liquid fuel tools include chain saws, lawn mowers, concrete saws, and pressure washers. When used properly and according to the manufacturer’s instructions, these types of tools are very dependable and safe. Like any other kind of tool, there can be some serious hazards involved if they are used improperly. The most serious hazards presented by these tools are dangerous exhaust fumes and vapors that can burn or explode. Proper ventilation, careful handling of fuel, and attention to fire safety can help reduce these hazards.

Hydraulic Tools Hydraulic tools are powered by a hydraulic pump which can be hand, foot, or engine powered, or even built into the tool itself. Hydraulics tools are used for the generation, control, and transmission of power by the use of pressurized liquids. Examples of hydraulic tools include jacks, presses, and impact wrenches. Hydraulic power tools present various hazards, including trip hazards or slipping hazards from oil leaks.

Safety Guidelines for Liquid Fuel Tools 1. Shut and cool down the engine before refilling a fuel tank. 2. Provide ventilation and/or proper respirators when using a

liquid fuel tool in an enclosed area to avoid breathing carbon monoxide.

3. Always transport fuel in approved flammable liquid containers. 4. Have fire extinguishers available when working. 5. Always wear foot, eye, face, head, and ear protection when

required.


Safety Guidelines for Powder Actuated Tools

1. Never point a powder-actuated tool at another person. 2. Use an alignment guide when shooting a fastener into an existing hole. 3. Do not fire fasteners into materials that would let them pass through to the other side. 4. Stay at least 3 inches away from the edges or corners of materials like brick or concrete. 5. Stay ½ inch away from a steel corner or edge. In steel, the fastener must not come any

closer than ½ inch from a corner or an edge. 6. Do not drive fasteners into hard or brittle materials that might chip or splatter, or make the

fastener ricochet. 7. Always wear hand, eye, ear, and face protection, as well as long-sleeved shirt and pants.

Powder Actuated Tools A powder-actuated tool (often called a "Hilti gun" or a "Ramset gun" after their manufacturing companies), is a nail gun used in construction to join materials to hard substrates such as steel and concrete. This technology relies on a controlled explosion created by a small chemical propellant similar to the process that discharges a firearm. An example of a powder-actuated tool is a concrete fastener. Powder actuated tools come in both low and high velocity types. Either design can be dangerous to operate. Low velocity tools introduce a piston into the chamber. The propellant acts on the piston, which then drives the fastener into the substrate. In high velocity tools, the propellant acts directly on the fastener, similar to a firearm on a bullet.


MACHINE MAINTENANCE, REPAIRS AND

INSPECTION

Who can repair machinery? Only authorized individuals, such as the shop manager / supervisor, or a designee can repair machinery. User manuals or SOPs must be consulted and followed when maintaining or repairing equipment. Any piece of machinery that undergoes repair, whether it is repaired in-house or sent out, must have documentation which clearly outlines the extent of the repairs. Records of machinery repair must be maintained in the shop and be made available for regulatory review if requested.

What type of machinery must have routine inspections? All heavy machinery that is continuously in use must have routine safety or maintenance inspections. Inspections must be documented using machine specific checklists or general maintenance logs that demonstrate routine review and inspection of machine parts and performance.

How do I report a machine in need of maintenance or repairs? You must immediately notify the shop manager / supervisor, or their designee, of needed maintenance or repairs on any piece of shop equipment. Place a “red tag” on the power cord or by some other means identify the equipment as being defective and needing repair. Conduct Lock out/Tag out (LOTO) procedures if any machine guard is removed, if starting a machine would put anyone in harm’s way, or before any maintenance or repairs are conducted. Refer to the LOTO section of this manual for more information on LOTO procedures.


QUIZ - MACHINE AND TOOL SAFETY

1. True or False? The point of operation on the drill press does not have to be guarded.

2. What would you use a Job Safety Analysis (JSA) for? a. Planning a work project b. Learning about a piece of machinery or shop process c. Figuring out what PPE to wear when planning to use shop equipment d. Understanding hazards and their controls in your work area e. All the above

3. Who can provide training on the safe usage of shop machinery?

a. Co-workers b. Shop Managers / Supervisors c. Friends

4. True or False?

Gloves must be used when operating a milling machine.

5. Which of the following offers the best protection when operating a grinder? a. Safety Glasses b. Face shield c. Both a and b

6. If you see a fellow shop user who has long hair using a hand-held power grinder, what PPE should they be wearing? a. Eye and face protection b. Hair Net c. Leather gloves d. Long sleeve shirt e. All the above

7. True or False?

Lock out/Tag out (LOTO) must be in place when replacing a band saw blade.

8. What jewelry should you remove before operating a table saw? a. Dangling Earrings b. Necklace / Neck chain c. Wedding Ring d. Wrist watch e. All the above f. A, B and C only


* Quiz Answers:

1. False 2. e 3. b 4. false 5. c 6. e 7. True 8. e

section 4: machine, guards and tool safety · protection whenever available. pull-back long hair,...

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