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Safety in the Machine Shop

Introduction
All hands and machine tools can be dangerous if used
improperly or carelessly. Working safely is of the first things a
student should learn because of the safe way is usually the
most correct and efficient way. A person learning to operate
machine tools must first learn the safety regulations and
precautions for each tool or machine. Far too many accidents
are caused by carelessness in work habits and it can affect
someone for the rest of his life. A loss of eyesight due to not
wearing of safety glasses, or the loss of a limb due to loose
clothing caught in the machine. It is easier and much more
sensible to develop safe work habits than to suffer the
consequences of an accident. Safety is everyone’s business and
responsibility. THINK SAFE, WORK SAFE, and BE SAFE.
Safety on the job
Safety on the job
The safety programs initiated by accident prevention
associations, safety councils, government agencies, and
industrial firms are constantly attempting to reduce the
number of industrial accidents. Accidents don’t just happen;
they are caused. The cause of an accident can usually be
traced to carelessness on someone’s part. Accidents can be
avoided, and a person learning the machine shop trade must
first develop safe work habits. A safe worker should:
□ Be neat, tidy, and safely dressed for the job he or
she is performing.
□ Develop a responsibility for personal safety and
the safety of fellow workers.
□ Think safety and work safety at all times.
Safety in the shop
Safety in the machine shop may be divided into two broad categories:
□ Those practices which will prevent injury to the workers.
□ Those practices which will prevent damage to machines and
equipment results in personal injuries.

In considering these categories, one must consider 1. personal grooming,

2. proper housekeeping, 3. safe work practices and 4. fire prevention.
1. Personal Grooming
The following rules should be observed when working in the machine shop.
1. Always wear approved safety glasses in any area of the machine shop. Most plants
now insist that all employees and visitors wear safety glasses or some eye protection
device when entering the shop area.
NOTE: Never think that because you are wearing glasses your eyes are safe. If the
lenses are not made of approved safety shatterproof glass, serious eye injury can result.
2. Never wear loose clothing when operating any machine.
a. Always roll up your sleeves or short sleeves
b. Clothing should be made of hard, smooth material that will not catch easily in a
machine. Loose fitting sweaters should not be worn for this reason.
c. Remove or tuck in a necktie before starting a machine. If you want to wear a
tie, make it a bow tie.
d. When wearing a shop apron, always tie it at the back and never in front of you
so that the apron strings will not get caught in rotating parts.
3. Remove wrist watches, rings, and bracelets; these can get
caught in the machine causing painful and often serious
injury.
4. Never wear gloves when operating a machine.
5. Long hair must be protected by a hair net or approved
protective shop cap.
6. Canvass shoes or open toe sandals must never be worn in a
machine shop since they offer no protection to the feet against
sharp chips or falling objects. In industry, most companies
make it mandatory for the employees to wear safety shoes
2. Housekeeping
The operator should remember that good housekeeping will never interfere with
safety or efficiency: therefore, the following points should be observed.
1. Always stop the machine before you attempt to clean it.
2. Always keep the machine and hand tools
clean. Oily surfaces can be dangerous. Metal
chips left on the table surface may interfere
with the safe clamping of a workpiece.
3. Always use a brush and not a cloth to
removed any chips.
4. Oily surfaces should be cleaned with a cloth.
5. Do not place tools and materials on the machine table – use a bench near the
machine.
6. Keep the floor free from oil and grease.
7. Never place tools or materials on the floor close to a machine where they will
interfere with the operator’s ability to move safely around the machine.
8. Sweep up the metal chips on the floor frequently. They become embedded in the
soles of shoes and can cause dangerous slippage if a person walks on a concrete
floor.
9. Return bar stock to the storage rack after cutting off the required length.
10. Never use compressed air to remove chips from a machine. Not only it is
dangerous practice because of flying metal chips, but small chips can become
wedged between machine parts and cause undue wear.
3. Safe Work Practices
1. Do not operate any machine before understanding its
mechanism and knowing how to stop it quickly. Knowing
how to stop the machine quickly can prevent a serious
injury.
2. Before operating any machine, be sure that the safety
devices are in place and in working order. Remember,
safety devices are for the operator’s protection and should
not be removed.
3. Always disconnect the power and lock it off at the switch box when making
repairs to any machine. A sign should be placed on the machine noting that it is
out of order.
4. Always be sure that the cutting tool and the workpiece are properly mounted
before starting the machine.
5. Keep hands away from moving parts. It is dangerous practice to “feel” the surface
of the revolving work or to stop a machine by hand.
6. Always stop a machine before measuring, cleaning, or making any adjustments. It
is dangerous to do any type or work around moving parts of a machine.
7. Never use a rag near the moving parts of a machine. The rag maybe drawn into the
machine, along with the hand that is holding it.
8. Never have more than one person operate a machine at the same time.
9. Get first aid immediately for any injury, no matter how small. Report the injury
and be sure that the smallest cut is treated to prevent the chance of a serious
infection.
10. Before you handle any workpiece, remove all burrs and sharp edges with a file.
 11. Do not attempt to lift heavy or odd shaped objects which are difficult to
handle on your own.
12. Be sure the work is clamped securely in the vise or to a machine table.
13. It is safer to pull a wrench than to push on it.
14. Never start a machine until you are sure that the cutting tool and machine parts
will clear the workpiece.
15. Use the proper wrench for the job, and replace nuts when worn out.
4. Fire Prevention
1. Always dispose oily rags in proper metal containers.
2. Be sure of the proper procedure before lighting a gas furnace.
3. Know the location and the operation of every fire
extinguisher.
4. Know the location of a nearest fire exit from the
building.
5. Know the location of the nearest fire-alarm box and
its operating procedure.
Machine Shop Safety Rules
General
1. These job safety rules are in addition to the General Safety Rules. You must know
and follow both.
2. Workers must not remove or make ineffective any safeguards, unless authorized.
Safeguards removed for repairs must be replaced promptly or temporary guards
installed.
3. Machines and equipment shall be operated by authorized personnel only.
4. No machine shall be left unattended while it is in motion.
5. Cleaning, oiling or adjusting any machine shall not be done while the machine is in
motion.
6. Materials to be machined shall be securely fastened or clamped to the working
surfaces before starting the machine.
7. Keys or other adjusting tools must never be left so that they may creep, be thrown,
or fall when machine is started.
8. Use a brush, special tool or hook to remove chips, shavings or other material from
work. Flowing shavings shall not be handled with bare hands; metal hooks shall be
used.
9. Revolving shafting, although apparently smooth, will catch loose or ragged
clothing, hair or wiping rags. Proper clothes and caution are always necessary when
working around any revolving machinery.
10. When tightening work in chuck jaws with chuck wrench, operator shall see that
wrench fits properly; operator should take proper stance when tightening jaws to
prevent falling if wrench slips.
11. When placing or removing heavy castings or billets from machines, operator shall
get help or crane service to prevent injury.
12. Operators shall keep hands away from cutters and bars while operating machines.
Operators shall keep hands off work while machine is in operation.
13. Operators shall stand so that they can easily reach the machine controls.
14. Cutters and tools shall be in the clear before machines are started.
15. Clean-up chips, spills, etc., on and around machinery after each use.
Lathes
1. All materials shall be properly secured in chucks and
collets before machines are started.
2. Do not leave chuck wrench in chuck after removing work
from chuck.
3. Keep hands off chuck rims when lathe is in motion.
4. Do not attempt to screw chuck on lathe spindle with power
on, as it may get cross-threaded and cause an accident.
5. Safety-type lathe dogs shall be used when turning work on
centers.
6. See that tail stock, tool holder and work are properly
clamped before turning on power.
7. It is dangerous to shift step pulley belts with the hands while the belts are in motion
with power on; use a belt pole or other suitable stick.
8. Do not attempt to adjust a tool while the lathe is running.
9. Operators shall not attempt to use micrometers on revolving work.
Drill Press
1. Never attempt to hold the work under the drill by hand;
clamp it securely to the table before starting the machine.
2. When tightening drill in chuck of drill press, remove release
key before you start machine, or your arm may be twisted
around spindle. Never leave key in chuck.
3. Use drills properly sharpened to cut to the right size.
4. Run the drill only at the correct speed; forcing or feeding too
fast may cause broken drills and result in serious injury.
5. If the work should slip from clamp, never attempt to stop it
with your hands. Stop the machine to make any adjustment
or repair.
6. Drills, reamers, etc., must never be forced by exerting
excess pressure on the feed lever. Tools may break and cause
injury.
Milling Machines

1. All work shall be secured properly and all loose

objects removed from tables before machines are
operated.
2. Cutters shall be checked for cracks or breaks before
mounting and shall be securely mounted before
operations are started.
3. Operators shall keep head and hands away from
cutters when machine is in operation.
4. File tangs or other makeshift drifts shall not be used
to remove taper shank tools. Proper drifts are
available in tool rooms.
5. Safety guards shall be placed around any work item
extending beyond machine table.
6. Milling cutters and other hardened tools shall not be
struck with steel hammer. Blocks of wood, rawhide,
or copper hammers should be used
7. Proper feeds and speeds shall be selected before
operations are started.
8. Machines shall be stopped before any attempts are
made to measure or to check work.
9. Guards and baffles shall be used to protect others from
flying chips, oil or coolants.
10. Operators shall be sure that cutters and feeds are
turning in the proper direction so the cutters will not
climb up or jam. Such an accident can cause injury to
the work, the machine, and to the operator as well.
Grinders
1. Caution: All grinding wheels operate at dangerous
speeds.
2. See that the grinding wheel fits easily on the spindle. It is
dangerous to force it on, nor should it be too loose.
3. Washers or flange facings or compressible material shall
be fitted between the wheel and its flanges. If blotting
paper is used, it should not be thicker than .025 inch.
4. After a wheel is mounted, allow it to develop full
operating speed for at least one minute; meanwhile, stand
to one side and out of danger.
5. Never apply the work until this speed test has been made
and the wheel has been properly dressed.
6. Under no condition should the wheel revolve faster than
the safe R.P.M. recommended by the manufacturer as
shown on the label
7. Do not force work against a cold wheel, but apply it
gradually, giving the wheel an opportunity to
warm, thus reducing the chance of breakage. This
applies to starting work in the mornings in cold
rooms and to new wheels which have been stored
in a cold place.
8. Wheel dressers, except the diamond type, shall be
equipped with guards over the tops of the cutters to
protect against flying pieces, broken cutters, or
wheel particles.
9. Operator shall see that wheel turns freely and is
properly mounted before operating.
10. All wheels should be given the "ring" test before
they are mounted on machines.
11. Gloves should not be worn while operating
grinders
12. Dust collectors or other exhaust systems shall be in
operation during grinding operations on machines
so equipped
13. Tools or other loose objects shall be kept off
machines in operation
14. Wheel guards shall be kept in place and in good
condition while machine is in operation.
15. Safe operating speeds are marked on wheels by
manufacturers
16. Operators shall not run wheels faster than recommended speeds
17. Operators shall avoid standing directly in front of grinding wheels, especially when
starting
18. Wheels loaded or clogged with metal shall not be used until dressed.
19. Grinding wheels out of round or out of balance shall be trued before using.
20. Eye protective equipment with side shields shall be worn while
grinders are being operated
21. Grindings wheels shall be equipped with tool rests, same must
not be worn more than one-eighth inch from stone and work
held firmly thereon.
22. Grindings wheels shall be equipped with tool rests, same must
not be worn more than one-eighth inch from stone and work
held firmly thereon
23. It is unsafe to adjust a work-rest while the grinding wheel is in
motion. The rest may slip and break the wheel
24. The side of an emery wheel shall not be used for grinding
unless it is a special-type wheel for that purpose
25. Be especially careful when grinding narrow tools. They are apt
to catch between the rest and the wheel
Planers, Shapers and Slotters

1. Jobs shall be securely mounted and all tools

removed from tables before machines are
started.
2. Machine stroke shall be properly adjusted so
as to clear work and machine tables.

3. Operators shall stand clear of work

that projects over side of planer tables.
4. Operators shall not try to adjust stroke
or position of ram while cut is being
taken.
5. Operators should stand so machine controls are
easily reached.
6. While machines are in operation, hands shall
be kept away from clapper boxes. Adjustment
shall not be made to tools when clapper boxes
are raised.
7. Screens shall be provided against flying chips
or cuttings to protect other employees working
nearby.
8. Operators should take proper stance when
pulling on long wrenches to bolt down work on
machines to prevent falling and strain should
the wrench slip.