MasterCraft 054-7120-4 User manual

INSTRUCTION MANUAL
ANGLE GRINDER
054-7120-4

ANGLE GRINDER - 054-7120-4
If any parts are
missing or damaged,
or if you have any
questions, please call
our toll-free helpline
at 1-800-689-9928.
Read and understand this instruction manual
thoroughly before using the product. It contains
important information for your safety as well as
operating and maintenance advice.
Keep this instruction manual for future use. Should
this product be passed on to a third party, then this
instruction manual must be included.

ANGLE GRINDER - 054-7120-4
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TABLE OF CONTENTS
TECHNICAL SPECIFICATIONS 3
SAFETY GUIDELINES 4–9
DESCRIPTION 10
OPERATING INSTRUCTIONS 11–16
MAINTENANCE 17–18
TROUBLESHOOTING 19
PARTS LIST 20–21
WARRANTY 22–23

ANGLE GRINDER - 054-7120-4
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RATED POWER INPUT 5A
RATING 120 V ~ 60 Hz
RATED SPEED 11,000 RPM
WHEEL DIAMETER 4 1/2" (115 mm)
ARBOR SIZE 5/8"
RECOMMENDED WHEEL Type 27
TOOL WEIGHT 3 lb 15 oz (1.79 kg)
TECHNICAL SPECIFICATIONS

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WARNING!
Safety symbols in this Instruction Manual are used to flag possible dangers. The safety
symbols and their explanations require your full understanding. The safety warnings do
not, by themselves, eliminate any danger, nor are they substitutes for proper accident
prevention measures.
WARNING!
This Safety Alert Symbol indicates caution, warning, or danger. Failure to obey a safety
warning can result in serious injury to yourself or others. To reduce the risk of injury, fire, or
electric shock, always follow the safety precautions.
Know your tool
To operate this tool, carefully read this Instruction Manual and all labels affixed to the Angle Grinder
before using. Keep this manual available for future reference.
Important
This tool should only be serviced by a qualified service technician. For more information, call the toll-
free helpline at 1-800-689-9928.
Read all instructions thoroughly
Save these instructions
General power tool safety warnings
WARNING!
Read all safety warnings and instructions. Failure to follow the warnings and instructions
may result in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
The term “power tool” in the warnings refers to your mains-operated (corded) power tool or
battery-operated (cordless) power tool.
SAFETY GUIDELINES

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Work area safety
• Keep the work area clean and well lit. Cluttered or dark areas invite accidents.
• Do not operate power tools in explosive atmospheres, such as in the presence of
flammable liquids, gases or dust. Power tools create sparks, which may ignite the dust or fumes.
• Keep children and bystanders away while operating a power tool. Distractions can cause
you to lose control.
Electrical safety
• Power tool plugs must match the outlet. Never modify the plug in any way. Do not use
any adapter plugs with earthed (grounded) power tools. Unmodified plugs and matching
outlets will reduce the risk of electric shock.
• Avoid body contact with earthed or grounded surfaces such as pipes, radiators, ranges
and refrigerators. There is an increased risk of electric shock if your body is earthed or grounded.
• Do not expose power tools to rain or wet conditions. Water entering a power tool will increase
the risk of electric shock.
• Do not abuse the cord. Never use the cord for carrying, pulling or unplugging the power
tool. Keep the cord away from heat, oil, sharp edges or moving parts. Damaged or
entangled cords increase the risk of electric shock.
• When operating a power tool outdoors, use an extension cord suitable for outdoor use.
Use of a cord suitable for outdoor use reduces the risk of electric shock.
• If operating a power tool in a damp location is unavoidable, use a ground-fault circuit
interrupter (GFCI) protected supply. Use of a GFCI reduces the risk of electric shock.
Personal safety
• Stay alert, watch what you are doing and use common sense when operating a power tool.
Do not use the tool while tired or under the influence of drugs, alcohol, or medication.
A moment of inattention while operating power tools may result in serious personal injury.
• Use personal protective equipment. Always wear eye protection. Protective equipment such
as dust mask, non-skid safety shoes, hard hat, or hearing protection, used for appropriate conditions,
will reduce personal injuries.
• Prevent unintentional starting. Ensure the switch is in the off-position before connecting
to power source and/or battery pack, picking up or carrying the tool. Carrying power tools
with your finger on the switch or energising power tools that have the switch on invites accidents.
SAFETY GUIDELINES

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• Remove any adjusting key or wrench before turning the power tool on. A wrench or a key
left attached to a rotating part of the power tool may result in personal injury.
• Do not overreach. Keep proper footing and balance at all times. This enables better control of
the power tool in unexpected situations.
• Dress properly. Do not wear loose clothing or jewellery. Keep your hair, clothing and gloves
away from moving parts. Loose clothes, jewellery or long hair can be caught in moving parts.
• If devices are provided for the connection of dust extraction and collection facilities, ensure
that these are connected and properly used. Use of these devices can reduce dust-related hazards.
Power tool use and care
• Do not force the power tool. Use the correct power tool for your application. The correct
power tool will do the job better and more safely at the rate for which it was designed.
• Do not use the power tool if the switch does not turn it on and off. Any power tool that
cannot be controlled with the switch is dangerous and must be repaired.
• Disconnect the plug from the power source and/or the battery pack from the power tool
before making any adjustments, changing accessories, or storing power tools. Such
preventive safety measures reduce the risk of starting the power tool accidentally.
• Store idle power tools out of the reach of children and do not allow persons unfamiliar
with the power tool or these instructions to operate the power tool. Power tools are
dangerous in the hands of untrained users.
• Maintain power tools. Check for misalignment or binding of moving parts, breakage of
parts and any other condition that may affect the power tool’s operation. If damaged,
have the power tool repaired before use. Many accidents are caused by poorly maintained
power tools.
• Keep cutting tools sharp and clean. Properly maintained cutting tools with sharp cutting edges
are less likely to bind and are easier to control.
• Use the power tool, accessories, tool bits, etc. in accordance with these instructions,
taking into account the working conditions and the work to be performed. Use of the power
tool for operations different from those intended could result in a hazardous situation.
Service
• Have your power tool serviced by a qualified repair person using only identical
replacement parts. This will ensure that the safety of the power tool is maintained.
SAFETY GUIDELINES

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Safety guidelines for angle grinder
• This power tool is intended to function as a grinder. Read all safety warnings,
instructions, illustrations and specifications provided with this power tool. Failure to follow
all instructions listed below may result in electric shock, fire and/or serious injury.
• Operations such as sanding, wire brushing, polishing or cutting-off are not recommended
to be performed with this power tool. Operations for which the power tool was not designed
may create a hazard and cause personal injury.
• Do not use accessories that are not specifically designed and recommended by the tool
manufacturer. Just because the accessory can be attached to your power tool, safe operation is
not assured.
• The rated speed of the accessory must be at least equal to the maximum speed marked
on the power tool. Accessories running faster than their RATED SPEED can break and fly apart.
• The outside diameter and the thickness of your accessory must be within the capacity rating
of your power tool. Incorrectly sized accessories cannot be adequately guarded or controlled.
• The arbor size of wheels, flanges or any other accessory must properly fit the spindle
of the power tool. Accessories with arbor holes that do not match the mounting hardware of the
power tool will run out of balance, vibrate excessively and may cause loss of control.
• Do not use a damaged accessory. Before each use inspect the accessory. If the power tool
or accessory is dropped, inspect it for damage or install an undamaged accessory. After inspecting
and installing an accessory, position yourself and bystanders away from the plane of the rotating
accessory and run the power tool at maximum no-load speed for one minute. Damaged accessories
will normally break apart during this test time.
• Wear personal protective equipment. Depending on application, use a face shield, safety
goggles or safety glasses. As appropriate, wear a dust mask, hearing protectors, gloves
and workshop apron capable of stopping small abrasive or workpiece fragments. The eye
protection must be capable of stopping flying debris generated by various operations.
The dust mask or respirator must be capable of filtrating particles generated by your operation.
Prolonged exposure to high intensity noise may cause hearing loss.
• Keep bystanders a safe distance away from work area. Anyone entering the work area
must wear personal protective equipment. Fragments of workpiece or of a broken accessory
may fly away and cause injury beyond the immediate area of operation.
• Hold the power tool by the insulated gripping surfaces only when performing an
operation where the grinding accessory may contact hidden wiring or its own cord. A
cutting accessory contacting a “live” wire may make exposed metal parts of the power tool “live”
and could give the operator an electric shock.
• Position the cord clear of the spinning accessory. If you lose control, the cord may be cut or
snagged and your hand or arm may be pulled into the spinning accessory.
SAFETY GUIDELINES

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• Never lay the power tool down until the accessory has come to a complete stop. The
spinning accessory may grab the surface and pull the power tool out of your control.
• Do not run the power tool while carrying it at your side. Accidental contact with the spinning
accessory could snag your clothing, pulling the accessory into your body.
• Regularly clean the power tool’s air vents. The motor’s fan will draw the dust inside the housing
and excessive accumulation of powdered metal may cause electrical hazards.
• Do not operate the power tool near flammable materials. Sparks could ignite these materials.
• Do not use accessories that require liquid coolants. Using water or other liquid coolants may
result in electrocution or shock.
• The label on your tool may include the following symbols. The symbols and their
definitions are as follows:
V ..................... Volts
A ..................... Amperes
Hz ................... Hertz
W .................... Watts
min ................. Minutes
............... Alternating current
............. Direct current
n0 ................... No-load speed
............... Class II Construction
…/min ........... Revolutions per minute
............... Grounding terminal
BPM ............... Beats per minute
.............. WARNING – To reduce the risk of injury, user must read instruction manual.
Further safety instructions for operation
Kickback and Related Warnings
• Maintain a firm grip on the power tool and position your body and arm to allow you to
resist kickback forces. Always use an auxiliary handle, if provided, for maximum control
over kickback or torque reaction during start-up. The operator can control torque reactions or
kickback forces, if proper precautions are taken.
SAFETY GUIDELINES

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• Never place your hand near the rotating accessory. The accessory may kickback over your
hand.
• Do not position your body in the area where the power tool will move if kickback occurs.
Kickback will propel the tool in the direction opposite to the wheel’s movement at the point of
snagging.
• Use special care when working corners, sharp edges, etc. Avoid bouncing and snagging
the accessory. Corners, sharp edges or bouncing have a tendency to snag the rotating accessory
and cause loss of control or kickback.
• Do not attach a saw chain, woodcarving blade or toothed saw blade. Such blades create
frequent kickback and loss of control.
Additional safety instructions for grinding operations
• Use only wheel types that are recommended for your power tool and the specific guard
designed for the selected wheel. Wheels for which the power tool was not designed cannot be
adequately guarded and are unsafe.
• The guard must be securely attached to the power tool and positioned for maximum
safety, so the least amount of wheel is exposed towards the operator. The guard helps to
protect the operator from broken wheel fragments, accidental contact with wheel and sparks that
could ignite clothing.
• Wheels must be used only for recommended applications. For example: do not grind with
the side of cut-off wheel. Abrasive cut-off wheels are intended for peripheral grinding; side forces
applied to these wheels may cause them to shatter.
• Always use undamaged wheel flanges that are of the correct size and shape for your
selected wheel. Proper wheel flanges support the wheel, thus reducing the possibility of wheel
breakage. Flanges for cut-off wheels may be different from grinding wheel flanges.
• Do not use worn down wheels from larger power tools. Awheel intended for a larger power
tool is not suitable for the higher speed of a smaller tool and may burst.
Contents:
Angle grinder, side handle, wrench, 4 1/2" grinding wheel and instruction manual.
WARNING!
Remove the angle grinder from the package and examine it carefully. Do not discard the
carton or any packaging material until all parts have been examined.
SAFETY GUIDELINES

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Know your tool
2
3
1
4
5
6
8
9 7
No. Description No. Description
1. Switch button 6. Grinding wheel
2. Spindle-lock button 7. Outer flange
3. Spindle 8. Guard-adjusting lever
4. Side handle 9. Wheel guard
5. Inner flange
Before attempting to use this tool, become familiar with all of its operating features and safety
requirements. For optimum performance and safety, read the following operating instructions carefully
before using.
WARNING!
Do not allow familiarity with the angle grinder to cause a lack of alertness. A fraction of a
second of carelessness is enough to cause severe injury.
DESCRIPTION

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ON/OFF switch (fig 1)
WARNING!
Firmly grasp the body of the tool and
the side handle before starting.
The tool is switched “ON” with the switch button
located at the side of the motor housing. The
switch can be locked in the “ON” position, a
convenience for long grinding operations. The
symbol “
O ” on the motor housing indicates OFF; the symbol “l” indicates ON.
1. Connect the power cord of your angle grinder to a standard household power outlet.
WARNING!
Always ensure that the switch is on the OFF position before you plug the tool into an outlet.
Failure to do this could result in accidental starting and cause serious injury.
2. To turn the tool ON without locking it, slide the switch button forward by applying pressure only at
the rear portion of the button.
3. To unlock the switch and turn the tool OFF, press and release the rear portion of the switch button;
it will return to the OFF position automatically.
FOR CONTINUOUS OPERATION:
4. Push the switch button forward to the ON position and press the front of the button down until the
switch clicks into position.
5. To unlock the switch and turn the tool OFF, press the rear of the button.
fig 1 Switch button
OPERATING INSTRUCTIONS

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Installing the side handle (fig 2)
The side handle is used to guide and balance the
tool and can be threaded into the front housing
on either side of the tool, depending on personal
preference and comfort. Use the side handle for
safe control and ease of operation.
WARNING!
Failure to unplug the tool from the
power source when assembling parts,
making adjustments, or changing application tools could result in accidental starting and
cause serious injury.
1. Unplug the angle grinder.
2. The side handle may be installed on the right side or the left side of the tool. Thread the side handle
into the desired operating position.
3. Securely tighten the side handle by turning it clockwise.
OPERATING INSTRUCTIONS
fig 2

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Adjust the guard (fig 3)
WARNING!
Failure to unplug the tool from the power
source when assembling parts, making
adjustments, or changing application
tools could result in accidental starting
and cause serious injury.
1. Unplug the angle grinder.
2. Press the guard-adjusting lever, and hold it to
loosen the guard.
3. Rotate the guard to the desired position and make sure the lever lines up with notches on the
guard.
4. Release the guard-adjusting lever to lock the guard and make sure the lever secures the guard.
WARNING!
Never use your grinder with the guard removed. It has been designed for use only with the
guard attached. Attempting to use the grinder with the guard removed will result in loose
particles being thrown against the operator and possibly serious personal injury.
WARNING!
Only use the guard with grinding wheels. Make sure that the guard-adjusting lever secures
the guard before plugging in. Keep the guard between you and wheel. Do not direct the
guard opening towards your body.
OPERATING INSTRUCTIONS
fig 3 Notch on the guard
Guard-
adjusting lever

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Mounting and removing the
guard (fig 4)
WARNING!
Failure to unplug the tool from the power
source when assembling parts, making
adjustments, or changing application
tools could result in accidental starting
and cause serious injury.
WARNING!
After extended use, the guard may become worn and need adjustment or replacing. Or, if you drop
the angle grinder and damage the guard, it may be necessary to replace it.
To remove the guard:
1. Unplug the angle grinder.
2. Remove the outer and the inner flanges away from the spindle.
3. With one hand depressing the guard-adjusting lever, rotate the guard so that the tabs on the guard
are aligned with the slots on the gear case cover and pull up on the guard.
To mount the guard:
1. Unplug the angle grinder.
2. Remove the outer and inner flanges away from the spindle.
3. Align the tabs on the guard with the slots on the gear case cover.
4. With one hand depressing the guard-adjusting lever, push the guard down until the guard tabs
engage and rotate freely in the groove on the gear case cover.
5. Adjust guard by depressing the guard-adjusting lever and rotate to desired position. Always
position wheel guard between operator and workpiece and direct sparks away from operator,
6. Release the guard-adjusting lever to lock the guard. Make sure the lever is secured in the notch of
the guard.
OPERATING INSTRUCTIONS
fig 4
Tabs on
the guard

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Mounting the wheel (fig 5-6)
WARNING!
Only use grinding wheels for which
the maximum safe operating speed
is rated at or above 13200 RPM.
Never use damaged or imbalanced
grinding wheels. Do not exceed the
recommended wheel diameter. Grinding
wheel type 27 is recommended for use
on this grinder.
WARNING!
Failure to unplug the tool from the power source when assembling parts, making
adjustments, or changing application tools could result in accidental starting and cause
serious injury.
1. Unplug the angle grinder.
2. Make sure that the guard is securely in place. Depress the spindle-lock button. Loosen the outer
flange with the supplied wrench while holding the spindle-lock button down (fig 6).
3. Place the inner flange on the spindle; make sure that the flange is positioned so that the shape of
the opening in the flange corresponds with the shape at the base of the spindle.
4. Place the grinding wheel on the spindle. Check the rated speed on the grinding wheel. DO NOT use
a wheel with a rated speed lower than the speed shown on the grinder nameplate.
5. Thread the outer flange on the spindle with the flat side of the flange facing up, making sure that
the opening in the wheel is positioned around the raised portion of the outer flange (fig 5).
6. Press the spindle-lock button to prevent
movement of the spindle.
7. Keep the spindle-lock button depressed;
tighten the threaded outer flange by turning it
clockwise with the wrench (fig 6).
WARNING!
Keep the guard between you and
the wheel. Do not direct the guard
opening toward your body.
OPERATING INSTRUCTIONS
fig 6
Spindle-lock
button
fig 5 Outer flange
Inner
flange
Spindle
Grinding
wheel

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Grinding operation
WARNING!
Only use grinding wheels for which the maximum safe operating speed is rated at or
above 13200 RPM. Never use damaged or imbalanced grinding wheels. Do not exceed the
recommended wheel diameter. Grinding wheel type 27 is recommended for use on this grinder.
WARNING!
Firmly grasp the body of the tool and the side handle before starting.
Grinding tips
• Use a clamp, vise or other practical means to hold your work, freeing both hands to control your tool.
Firmly grasp the body of tool and the side handle before starting and while the tool is in operation.
• Efficient grinding is achieved by controlling
the pressure and keeping the angle between
the wheel and the workpiece at 10° to 15°
(fig 7). If the wheel is flat, the tool is difficult to
control. If the angle is to steep, the pressure is
concentrated on a small area, causing burning
to the work surface.
• Move the angle grinder back and forth with
moderate pressure to avoid discoloring the
workpiece, overheating the workpiece and
creating ridges.
• Never use a cut-off wheel to grind a workpiece.
• Always hold the tool properly so that sparks and grinding dust fly away from the body.
• Start the tool before applying the accessory to the workpiece and let the tool come to full speed
before contacting the workpiece. Lift the tool from the workpiece before turning the tool OFF.
• When grinding with a new wheel be certain to grind while pulling tool backwards until wheel
becomes rounded on its edge. New wheels have sharp corners which tend to “bite” or cut into
workpiece when pushing forward.
WARNING!
Sparks are generated when grinding metal. Take care that no combustible material
presented in the area of flying sparks.
fig 7
10°~ 15°
OPERATING INSTRUCTIONS

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MAINTENANCE
General maintenance
Before each use:
1. Inspect the angle grinder, the ON/OFF switch, the cord and the accessories for damage.
2. Check for damaged, missing, or worn parts.
3. Check for loose screws, misalignment or binding of moving parts, or any other condition that may
affect the operation.
4. If abnormal vibration or noise occurs, turn the tool off immediately and have the problem
corrected before further use. Unplug the tool from power source before cleaning or performing any
maintenance.
WARNING!
Do not allow brake fluids, gasoline, petroleum-based products, penetrating oil, etc. come
into contact with plastic parts. These substances contain chemicals that can damage,
weaken, or destroy plastic.
WARNING!
When servicing, use only identical replacement parts. The use of any other parts may
create a hazard or cause damage to the product.
WARNING!
If the supply cord is damaged, it must be replaced with a specially prepared cord available
through the service organization.
WARNING!
Use only accessories that are recommended for this angle grinder by the manufacturer.
Accessories that may be suitable for one tool may become hazardous when used with
another tool.
WARNING!
Before cleaning or performing any maintenance, the tool should be unplugged from the
power supply.
WARNING!
To ensure safety and reliability, all repairs should be performed by a qualified service
technician.

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Lubrication
All of the bearings in this product are lubricated with a sufficient amount of high grade lubricant for the
life of the unit under normal operating conditions. Therefore, no further lubrication is required.
Cleaning
WARNING!
To avoid accidents always disconnect the tool from the power supply before cleaning or
performing any maintenance. The tool may be cleaned most effectively with compressed dry air.
Always wear safety goggles when cleaning tools with compressed air.
Ventilation openings and switch levers must be kept clean and free of foreign matter. Do not attempt to
clean by inserting pointed objects through openings.
Storage and handling of grinding wheels
When not in use, grinding wheels should be stored carefully in a rack or box to protect them from
chipping or breakage. All grinding wheels must be handled carefully to prevent dropping and bumping.
MAINTENANCE

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PROBLEM POSSIBLE CAUSES SOLUTIONS
The motor stops running The tool is disconnected from the power
source
Connect the tool to a power source
The plugs are not fully connected Make sure all plugs are connected
The tool is running slowly The grinding wheel is worn out Replace the grinding wheel on the
tool
If the problem remains unsolved after performing the checks described above, call the toll-
free helpline at 1-800-689-9928.
TROUBLESHOOTING