1/4" Die Grinder
Model
He64
WarninG: to prevent serious injury, user must read and understand
Owner’s Manual. SaVe tHiS ManuaL.
When unpacking, make sure that the product is intact and undamaged.
If any parts are missing or broken, please visit harborfreight.com/customer‑support/contact‑us
as soon as possible. Reference 56932.
®
Owner’s Manual &
Safety Instructions
26j
Page 2
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SaFety OperatiOn MaintenanceSetup
IMPORTANT SAFETY INFORMATION
General Power Tool Safety Warnings
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.
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.
Work Area Safety
1. Keep work area clean and well lit.
Cluttered or dark areas invite accidents.
2. 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.
3. Keep children and bystanders away
while operating a power tool. Distractions
can cause you to lose control.
Electrical Safety
1. 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 risk of electric shock.
2. 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.
3. Do not expose power tools to rain or wet
conditions. Water entering a power tool
will increase the risk of electric shock.
4. Do not abuse the cord. never use the cord
for carrying, pulling or unplugging the power
tool. Keep cord away from heat, oil, sharp
edges or moving parts. Damaged or entangled
cords increase the risk of electric shock.
5. 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.
6. 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
1. Stay alert, watch what you are doing and
use common sense when operating a
power tool. Do not use a power tool while
you are tired or under the influence of
drugs, alcohol or medication. A moment
of inattention while operating power tools
may result in serious personal injury.
2. 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.
3. 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 energizing power
tools that have the switch on invites accidents.
4. 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.
5. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the power tool in unexpected situations.
6. Dress properly. Do not wear loose clothing or
jewelry. Keep your hair, clothing and gloves
away from moving parts. Loose clothes, jewelry
or long hair can be caught in moving parts.
7. if devices are provided for the connection of
dust extraction and collection facilities, ensure
these are connected and properly used. Use of
dust collection can reduce dust-related hazards.
8. Do not let familiarity gained from frequent
use of tools allow you to become
complacent and ignore tool safety
principles. A careless action can cause
severe injury within a fraction of a second.
9. Only use safety equipment that has been approved
by an appropriate standards agency. Unapproved
safety equipment may not provide adequate
protection. Eye protection must be ANSI‑approved
and breathing protection must be NIOSH‑approved
for the specific hazards in the work area.
10. Avoid unintentional starting.
Prepare to begin work before turning on the tool.
11. Do not lay the tool down until it has come to
a complete stop. Moving parts can grab the
surface and pull the tool out of your control.
12. When using a handheld power tool,
maintain a firm grip on the tool with both
hands to resist starting torque.
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13. Do not depress the spindle lock when
starting or during operation.
14. Do not leave the tool unattended when it is plugged
into an electrical outlet. Turn off the tool, and
unplug it from its electrical outlet before leaving.
15. This product is not a toy.
Keep it out of reach of children.
16. People with pacemakers should consult their
physician(s) before use. Electromagnetic fields in
close proximity to heart pacemaker could cause
pacemaker interference or pacemaker failure.
In addition, people with pacemakers should:
• Avoid operating alone.
• Do not use with Power Switch locked on.
• Properly maintain and inspect to avoid
electrical shock.
• Properly ground power cord.
Ground Fault Circuit Interrupter (GFCI)
should also be implemented – it prevents
sustained electrical shock.
17. The warnings, precautions, and instructions
discussed in this instruction manual cannot
cover all possible conditions and situations
that may occur. It must be understood by the
operator that common sense and caution are
factors which cannot be built into this product,
but must be supplied by the operator.
Power Tool Use and Care
1. Do not force the power tool. use the correct
power tool for your application. The correct
power tool will do the job better and safer
at the rate for which it was designed.
2. 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.
3. Disconnect the plug from the power source and/
or remove the battery pack, if detachable, 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.
4. 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.
5. Maintain power tools and accessories.
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.
6. Keep cutting tools sharp and clean. Properly
maintained cutting tools with sharp cutting edges
are less likely to bind and are easier to control.
7. use the power tool, accessories and 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.
8. Keep handles and grasping surfaces
dry, clean and free from oil and grease.
Slippery handles and grasping surfaces
do not allow for safe handling and control
of the tool in unexpected situations.
Service
1. 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.
2. Maintain labels and nameplates on the tool.
These carry important safety information.
If unreadable or missing, contact
Harbor Freight Tools for a replacement.
Safety Warnings Common for
grinding, sanding, wire brushing,
or polishing Operations
1. this power tool is intended to function as a
grinder, sander, wire brush, or polisher 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.
2. Do not use accessories which are not
specifically designed and recommended
by the tool manufacturer. Just because the
accessory can be attached to your power tool,
it does not assure safe operation.
3. the rated speed of the accessories
must be at least equal to the operating
speed setting marked on the power
tool. Accessories running faster than their
rated speed can break and fly apart.
4. 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 controlled.
5. the arbour size of wheels, sanding drums
or any other accessory must properly fit the
spindle or collet of the power tool. Accessories
that do not match the mounting hardware of
the power tool will run out of balance, vibrate
excessively and may cause loss of control.
6. Mandrel mounted wheels, sanding drums,
cutters or other accessories must be fully
inserted into the collet or chuck. If the mandrel
is insufficiently held and/or the overhang of
the wheel is too long, the mounted wheel may
become loose and be ejected at high velocity.
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7. Do not use a damaged accessory. Before each
use inspect the accessory such as abrasive
wheels for chips and cracks, sanding drum
for cracks, tear or excess wear, wire brush
for loose or cracked wires. if power tool or
accessory is dropped, inspect 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.
8. Wear personal protective equipment.
Depending on application, use face shield,
safety goggles or safety glasses. as
appropriate, wear 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.
9. 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 immediate area of operation.
10. Hold power tool by insulated gripping surfaces
only, when performing an operation where the
accessory may contact hidden wiring or its own
cord. Cutting accessory contacting a ″live″ wire
may make exposed metal parts of the power tool
″live″ and could give the operator an electric shock.
11. always hold the tool firmly in your
hand(s) during the start-up. The reaction
torque of the motor, as it accelerates to
full speed, can cause the tool to twist.
12. use clamps to support workpiece whenever
practical. never hold a small workpiece in
one hand and the tool in the other hand while
in use. Clamping a small workpiece allows you
to use your hand(s) to control the tool. Round
material such as dowel rods, pipes or tubing
have a tendency to roll while being cut and may
cause the bit to bind or jump toward you.
13. 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.
14. 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.
15. after changing the bits or making any
adjustments, make sure the collet nut, chuck
or any other adjustment devices are securely
tightened. Loose adjustment devices can
unexpectedly shift, causing loss of control, loose
rotating components will be violently thrown.
16. 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.
17. 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.
18. Do not operate the power tool near flammable
materials. Sparks could ignite these materials.
19. Do not use accessories that require liquid
coolants. Using water or other liquid coolants
may result in electrocution or shock.
Kickback and Related Warnings
Kickback is a sudden reaction to a pinched or
snagged rotating wheel, sanding band, brush or
any other accessory. Pinching or snagging causes
rapid stalling of the rotating accessory which in turn
causes the uncontrolled power tool to be forced in
the direction opposite of the accessory’s rotation.
For example, if an abrasive wheel is snagged or
pinched by the workpiece, the edge of the wheel
that is entering into the pinch point can dig into the
surface of the material causing the wheel to climb
out or kick out. The wheel may either jump toward or
away from the operator, depending on direction of the
wheel’s movement at the point of pinching. Abrasive
wheels may also break under these conditions.
Kickback is the result of power tool misuse and/or
incorrect operating procedures or conditions and can be
avoided by taking proper precautions as given below.
1. Maintain a firm grip on the power tool and
position your body and arm to allow you to
resist kickback forces. The operator can control
kickback forces, if proper precautions are taken.
2. 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.
3. Do not attach a toothed saw blade. Such blades
create frequent kickback and loss of control.
4. always feed the bit into the material in
the same direction as the cutting edge is
exiting from the material (which is the same
direction as the chips are thrown). Feeding
the tool in the wrong direction causes the
cutting edge of the bit to climb out of the work
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and pull the tool in the direction of this feed.
5. When using rotary files, high-speed cutters
or tungsten carbide cutters, always have
the work securely clamped. These wheels
will grab if they become slightly canted in the
groove and can kickback. When a cut-off wheel
grabs, the wheel itself usually breaks. When
a rotary file, highspeed cutter or tungsten
carbide cutter grabs, it may jump from the
groove and you could lose control of the tool.
Safety Warnings Specific
for Grinding and Abrasive
Cutting‑Off Operations
1. use only wheel types that are recommended
for your power tool and only for
recommended applications. For example:
do not grind with the side of a cut-off
wheel. Abrasive cut-off wheels are intended
for peripheral grinding, side forces applied to
these wheels may cause them to shatter.
2. For threaded abrasive cones and plugs
use only undamaged wheel mandrels with
an unrelieved shoulder flange that are of
correct size and length. Proper mandrels
will reduce the possibility of breakage.
3. Do not “jam” a cut-off wheel or apply
excessive pressure. Do not attempt to make
an excessive depth of cut. Overstressing the
wheel increases the loading and susceptibility to
twisting or snagging of the wheel in the cut and
the possibility of kickback or wheel breakage.
4. Do not position your hand in line with and
behind the rotating wheel. When the wheel,
at the point of operation, is moving away from
your hand, the possible kickback may propel the
spinning wheel and the power tool directly at you.
5. When wheel is pinched, snagged or when
interrupting a cut for any reason, switch
off the power tool and hold the power tool
motionless until the wheel comes to a
complete stop. never attempt to remove the
cut-off wheel from the cut while the wheel
is in motion otherwise kickback may occur.
Investigate and take corrective action to eliminate
the cause of wheel pinching or snagging.
6. Do not restart the cutting operation in
the workpiece. Let the wheel reach full
speed and carefully re-enter the cut. The
wheel may bind, walk up or kickback if the
power tool is restarted in the workpiece.
7. Support panels or any oversized workpiece
to minimize the risk of wheel pinching and
kickback. Large workpieces tend to sag under
their own weight. Supports must be placed under
the workpiece near the line of cut and near the
edge of the workpiece on both sides of the wheel.
8. Dress appropriately. Wear leather leggings and fire
resistant footwear during use. Do not wear pants
with cuffs, shirts with open pockets, or any clothing
that can catch and hold molten metal or sparks.
Safety Warnings Specific for
Wire Brushing Operations
1. Be aware that wire bristles are thrown by
the brush even during ordinary operation.
Do not overstress the wires by applying
excessive load to the brush. The wire bristles
can easily penetrate light clothing and/or skin.
2. allow brushes to run at operating speed
for at least one minute before using them.
During this time no one is to stand in front
or in line with the brush. Loose bristles or
wires will be discharged during the run-in time.
3. Direct the discharge of the spinning wire
brush away from you. Small particles and
tiny wire fragments may be discharged at
high velocity during the use of these brushes
and may become imbedded in your skin.
Silicosis Safety Measures
Masonry grinding on materials such as concrete (which
contains crystalline silica) can cause silicosis (a serious
lung disease), cancer and death. To reduce
crystalline silica exposures in the workplace and
prevent silicosis and silicosis‑related deaths:
1. conduct air monitoring to
measure worker exposures.
2. use containment methods to control the hazard
and protect adjacent workers from exposure.
3. practice good personal hygiene to avoid
unnecessary exposure to silica dust.
4. Wear washable or disposable protective
clothes at the work site. Shower and change
into clean clothes before leaving the work site
to prevent contamination of cars, homes and
other work areas. Avoid skin exposure.
5. always wear a niOSH approved respirator and
safety goggles. Ventilate the work area properly.
6. provide periodic medical examinations
for all workers who may be
exposed to crystalline silica.
7. post signs to warn workers about
the hazard and to inform them about
required protective equipment.
8. provide workers with training that includes
information about health effects, work practices
and protective equipment for crystalline silica.
9. report all cases of silicosis to State health
departments and to OSHa or the Mine
Safety and Health administration (MSHa).
Page 6
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SaFety OperatiOn MaintenanceSetup
Vibration Safety
This tool vibrates during use. Repeated or
long‑term exposure to vibration may cause
temporary or permanent physical injury,
particularly to the hands, arms and shoulders. To
reduce the risk of vibration‑related injury:
1. Anyone using vibrating tools regularly or for an
extended period should first be examined by a
doctor and then have regular medical check‑ups
to ensure medical problems are not being caused
or worsened from use. Pregnant women or
people who have impaired blood circulation to
the hand, past hand injuries, nervous system
disorders, diabetes, or Raynaud’s Disease should
not use this tool. If you feel any medical or
physical symptoms related to vibration (such as
tingling, numbness, and white or blue fingers),
seek medical advice as soon as possible.
2. Do not smoke during use. Nicotine reduces
the blood supply to the hands and fingers,
increasing the risk of vibration‑related injury.
3. Wear suitable gloves to reduce the
vibration effects on the user.
4. Use tools with the lowest vibration when there
is a choice between different processes.
5. Include vibration‑free periods each day of work.
6. Grip tool as lightly as possible (while still keeping
safe control of it). Let the tool do the work.
7. To reduce vibration, maintain the tool as
explained in this manual. If any abnormal
vibration occurs, stop use immediately.
SaVe tHeSe
inStructiOnS.
GROUNDING
tO preVent eLectric SHOcK anD
DeatH FrOM incOrrect GrOunDinG
Wire cOnnectiOn: check with a
qualified electrician if you are in doubt
as to whether the outlet is properly grounded. Do
not modify the power cord plug provided with the
tool. never remove the grounding prong from the
plug. Do not use the tool if the power cord or plug
is damaged. if damaged, have it repaired by a
service facility before use. if the plug will not fit
the outlet, have a proper outlet installed by a
qualified electrician.
Grounded Tools: Tools
with Three Prong Plugs
3-prong plug and Outlet
1. Tools marked with “Grounding Required” have
a three wire cord and three prong grounding
plug. The plug must be connected to a properly
grounded outlet. If the tool should electrically
malfunction or break down, grounding provides
a low resistance path to carry electricity away
from the user, reducing the risk of electric
shock. (See 3-prong plug and Outlet.)
2. The grounding prong in the plug is connected
through the green wire inside the cord to the
grounding system in the tool. The green wire
in the cord must be the only wire connected
to the tool’s grounding system and must
never be attached to an electrically “live”
terminal. (See 3-prong plug and Outlet.)
3. The tool must be plugged into an appropriate outlet,
properly installed and grounded in accordance
with all codes and ordinances. The plug and outlet
should look like those in the preceding illustration.
(See 3-prong plug and Outlet.)
Page 7
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SaFetyOperatiOnMaintenance Setup
Double Insulated Tools: Tools
with Two Prong Plugs
Outlets for 2-prong plug
1. Tools marked “Double Insulated” do not
require grounding. They have a special
double insulation system which satisfies OSHA
requirements and complies with the applicable
standards of Underwriters Laboratories, Inc.,
the Canadian Standard Association,
and the National Electrical Code.
2. Double insulated tools may be used in either of the
120 volt outlets shown in the preceding illustration.
(See Outlets for 2-prong plug.)
Extension Cords
1. Grounded tools require a three
wire extension cord. Double Insulated tools can
use either a two or three wire extension cord.
2. As the distance from the supply outlet increases,
you must use a heavier gauge extension cord.
Using extension cords with inadequately sized wire
causes a serious drop in voltage, resulting in loss
of power and possible tool damage. (See table a.)
3. The smaller the gauge number of the wire, the
greater the capacity of the cord. For example,
a 14 gauge cord can carry a higher current
than a 16 gauge cord. (See table a.)
4. When using more than one extension cord
to make up the total length, make sure
each cord contains at least the minimum
wire size required. (See table a.)
5. If you are using one extension cord for more
than one tool, add the nameplate amperes
and use the sum to determine the required
minimum cord size. (See table a.)
6. If you are using an extension cord outdoors, make
sure it is marked with the suffix “W‑A” (“W” in
Canada) to indicate it is acceptable for outdoor use.
7. Make sure the extension cord is properly wired
and in good electrical condition. Always replace
a damaged extension cord or have it repaired
by a qualified electrician before using it.
8. Protect the extension cords from sharp objects,
excessive heat, and damp or wet areas.
taBLe a: recOMMenDeD MiniMuM Wire
GauGe FOr eXtenSiOn cOrDS* (120/240 VOLt)
naMepLate
aMpereS
(at full load)
eXtenSiOn cOrD
LenGtH
25´ 50´ 75´ 100´ 150´
0 – 2.0 18 18 18 18 16
2.1 – 3.4 18 18 18 16 14
3.5 – 5.0 18 18 16 14 12
5.1 – 7.0 18 16 14 12 12
7.1 – 12.0 18 14 12 10 ‑
12.1 – 16.0 14 12 10 ‑ ‑
16.1 – 20.0 12 10 ‑ ‑ ‑
* Based on limiting the line voltage drop to five volts at
150% of the rated amperes.
Symbology
Double Insulated
V
Volts
~
Alternating Current
a
Amperes
n
0
xxxx/min.
No Load Revolutions
per Minute (RPM)
WARNING marking concerning Risk
of Eye Injury. Wear ANSI‑approved
safety goggles with side shields.
WARNING marking concerning
Risk of Hearing Loss.
Wear hearing protection.
WARNING marking concerning Risk
of Respiratory Injury. Wear NIOSH‑
approved breathing protection rated
for the hazards in your work area.
Read the manual before
set‑up and/or use.
WARNING marking
concerning Risk of Fire.
Do not cover ventilation ducts.
Keep flammable objects away.
WARNING marking concerning
Risk of Electric Shock.
Properly connect power cord
to appropriate outlet.
Page 8
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Item 56932
SaFety OperatiOn MaintenanceSetup
Specifications
Electrical Rating 120VAC / 60Hz / 4A
No Load Speed n
0
:
25000/min
Max. Accessory
Diameter
2" Cut‑Off Wheel
3" Other Accessories
Collet Diameter 1/4″
Warning Symbols and Definitions
this is the safety alert symbol. it is used to
alert you to potential personal injury
hazards. Obey all safety messages that follow this
symbol to avoid possible injury or death.
indicates a hazardous
situation which, if not
avoided, will result in death or serious injury.
indicates a hazardous
situation which, if not
avoided, could result in death or serious injury.
indicates a hazardous
situation which, if not
avoided, could result in minor or moderate injury.
addresses practices not
related to personal injury.
SET UP ‑ BEFORE USE
read the entire iMpOrtant
SaFety inFOrMatiOn section at the
beginning of this manual including
all text under subheadings therein
before set up or use of this product.
tO preVent SeriOuS inJury FrOM
acciDentaL OperatiOn:
Make sure that the power Switch is in
the off-position and unplug the tool from
its electrical outlet before performing
any procedure in this section.
Functional Description
2
1
3
1. Power Switch
2. Collet Nut
3. Spindle
OPERATING INSTRUCTIONS
read the entire iMpOrtant
SaFety inFOrMatiOn section at the
beginning of this manual including
all text under subheadings therein
before set up or use of this product.
tO preVent SeriOuS inJury FrOM
acciDentaL OperatiOn:
Make sure that the power Switch is in
the off-position and unplug the tool from
its electrical outlet before performing
any procedure in this section.
Tool Changing
Installing Accessories
to prevent injury: Wear heavy-duty work gloves
when handling wire wheels and brushes.
these accessories are sharp and can cause injury.
1. The accessory MUST be:
• Rated to at least 25,000 RPM.
• No larger than 2" (cut‑off wheel) or
3" (other accessories) in diameter.
• Fitted with a 1/4" mandrel.
• Proven undamaged by inspection.
• A grinding wheel / burr / abrasive point, cut-
off wheel, sanding drum, wire brush or
polishing wheel (accessories not included).
2. Hold Spindle Lock in while turning Collet Nut
with included Wrench to loosen.
3. Insert accessory’s mandrel into Collet fully.
4. Using Wrench, securely tighten Collet Nut,
then release Spindle Lock.
Workpiece and Work Area Set Up
1. Designate a work area that is clean and well‑lit.
The work area must not allow access by children
or pets to prevent distraction and injury.
2. Route the power cord along a safe route
to reach the work area without creating a
tripping hazard or exposing the power cord to
possible damage. The power cord must
reach the work area with enough extra length
to allow free movement while working.
3. Secure loose workpieces using a vise or clamps
(not included) to prevent movement while working.
4. There must not be hazardous objects, such
as utility lines or foreign objects, nearby
that will present a hazard while working.
5. You must use personal safety equipment including,
but not limited to, ANSI‑approved eye and hearing
protection, as well as heavy‑duty work gloves.
6. Before beginning work, provide for sparks
and debris that will fly off the work surface.
Page 9
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General Instructions for Use
tO preVent SeriOuS inJury: Grip
the tool firmly in both hands.
1. Make sure that Power Switch is in the
off‑position, then plug in the tool.
2. Holding tool with both hands, slide
Power Switch to ON “I” position.
3. 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. Replace any
damaged accessory and repeat this test.
4. Allow tool to come up to full speed
before touching the work surface.
nOtice: tO preVent tOOL DaMaGe:
Only use the tool for 15‑20 minutes at a time.
Allow the tool to cool completely before next use.
WarninG! tO preVent SeriOuS inJury:
The tool will restart automatically if stalled.
For abrasive cutting-off operations:
WarninG! tO preVent SeriOuS inJury:
Do not grind with the side of the cut-off wheel.
abrasive cut-off wheels are intended for
peripheral grinding; side forces applied to these
wheels may cause them to shatter.
Apply the cut‑off wheel straight into the work
material using only the edge of the wheel,
allowing the tool to operate at full speed. If
the tool bogs down, use lighter pressure.
For grinding operations:
Apply the accessory to the work material
allowing the tool to operate at full speed. If
the tool bogs down, use lighter pressure.
To create a smoother surface, keep the
tool moving over the work surface.
For wire brushing operations:
WarninG! tO preVent SeriOuS inJury:
these accessories are sharp and can cause
injury. Do not exceed maximum rated speed of
brush. Do not use a damaged brush, replace
damaged brushes immediately. Damaged or
worn brushes will forcefully shoot wires into all
objects.
Apply the accessory to the work material
allowing the tool to operate at full speed. If
the tool bogs down, use lighter pressure.
For sanding operations:
WarninG! tO preVent SeriOuS inJury:
a. Thoroughly clean work surface of dirt and debris.
b. Periodically, stop the tool and check
for accessory wear. Replace worn
sanding accessory as needed.
c. Apply the accessory to the work material
allowing the tool to operate at full speed. If
the tool bogs down, use lighter pressure. To
ensure even sanding, keep the tool moving
in a uniform pattern over the work surface.
For masonry grinding operations:
WarninG! tO preVent SeriOuS inJury:
always wear a niOSH approved respirator.
Ventilate the work area properly.
Apply the accessory to the work material,
allowing the tool to operate at full speed. If
the tool bogs down, use lighter pressure.
5. tO preVent acciDentS, aFter uSe:
Turn off the tool by sliding Power Switch to OFF “O”
position.
WarninG! tO preVent SeriOuS inJury:
allow the tool to come to a complete stop
before setting it down.
Unplug the tool. Clean, then store the
tool indoors out of children’s reach.
®
Page 10
For product assistance, please visit harborfreight.com/customer-support/contact-us
Item 56932
SaFety OperatiOn MaintenanceSetup
MAINTENANCE AND SERVICING
procedures not specifically explained in
this manual must be performed only by a
qualified technician.
tO preVent SeriOuS inJury FrOM
acciDentaL OperatiOn:
Make sure that the power Switch is in
the off-position and unplug the tool from
its electrical outlet before performing
any procedure in this section.
tO preVent SeriOuS inJury
FrOM tOOL FaiLure:
Do not use damaged equipment.
if abnormal noise or vibration occurs, have
the problem corrected before further use.
Cleaning, Maintenance,
and Lubrication
1. BeFOre eacH uSe, inspect the general
condition of the tool. Check for:
• loose hardware,
• misalignment or binding of moving parts,
• damaged cord/electrical wiring,
• cracked or broken parts, and
• any other condition that may
affect its safe operation.
2. aFter uSe, wipe external surfaces
of the tool with clean cloth.
3. periODicaLLy, wear ANSI‑approved
safety goggles and NIOSH‑approved
breathing protection and blow dust and grit out
of the motor vents using dry compressed air.
4. WarninG! tO preVent SeriOuS inJury:
if the supply cord of this power tool
is damaged, it must be replaced only
by a qualified service technician.
Accessory Storage and Handling
1. Handle accessories carefully to prevent
dropping or bumping. Do not use wheels
that have been dropped or bumped.
2. Store accessories in shelves, racks, boxes,
or drawers. Keep storage area dry and
above freezing. Any grinding or cut‑off
wheels exposed to humidity or freezing
temperatures must not be used.
Page 11
For product assistance, please visit harborfreight.com/customer-support/contact-us
Item 56932
SaFetyOperatiOnMaintenance Setup
Troubleshooting
problem possible causes Likely Solutions
Tool will not start. 1. Cord not connected.
2. No power at outlet.
3. Internal damage or wear. (Carbon
brushes or switch, for example.)
1. Check that cord is plugged in.
2. Check power at outlet. If outlet is
unpowered, turn off tool and check
circuit breaker. If breaker is tripped,
make sure circuit is right capacity for
tool and circuit has no other loads.
3. Have technician service tool.
Tool operates slowly. 1. Forcing tool to work to fast.
2. Extension cord too long or
cord diameter too small.
1. Allow tool to work at its own rate.
2. Eliminate use of extension cord.
If an extension cord is needed, use one
with the proper diameter for its length and
load. See “Extension Cords” on page 7.
Performance
decreases over time.
Carbon brushes worn or damaged. Have qualified technician replace brushes.
Excessive noise
or rattling.
Internal damage or
wear. (Carbon brushes or
bearings, for example.)
Have qualified technician service tool.
Overheating. 1. Forcing tool to work too fast.
2. Blocked motor housing vents.
3. Motor being strained by long or
small diameter extension cord.
1. Allow tool to work at its own rate.
2. Wear ANSI‑approved safety goggles
and NIOSH‑approved dust mask/
respirator while blowing dust out of
motor using compressed air.
3. Eliminate use of extension cord.
If an extension cord is needed, use one
with the proper diameter for its length and
load. See “Extension Cords” on page 7.
Tool does not
operate effectively.
1. Accessory loose.
2. Accessory damaged, worn or
wrong type for the material.
1. Confirm accessory arbor is correct
and Collet Nut is tight.
2. Check condition and type of accessory.
Use only proper type of accessory
in good condition.
Follow all safety precautions whenever diagnosing or servicing
the tool. Disconnect power supply before service.
record product’s Date code Here:
note: if product has no date code, record month and year of purchase instead.
note: Replacement parts may be available for this item.
To view all currently available replacement parts, please visit harborfreight.com/parts
Specify UPC 193175545404 when ordering parts.
3‑YEAR LIMITED WARRANTY
This HERCULES tool is warranted to the original purchaser to be free from defects in materials and
workmanship for a period of three (3) years beginning on the date of purchase. To obtain warranty
service, visit your local Harbor Freight retail store. Warranty registration is not required. The product
or part must be returned to us with proof of purchase (e.g. in‑store receipt or packing slip/invoice)
and may require shipment by purchaser to a service center at purchaser’s expense. If our inspection
verifies a covered defect in materials or workmanship during the warranty period, we will, at our option,
repair or replace the defective product. We will return repaired products within a reasonable time at our
expense, but if we determine that there is no defect, or that the defect resulted from causes not within
the scope of our warranty, then we will return the product to you if you pay return shipping costs.
This warranty does not cover any failure or damage that we determine is due directly or indirectly
to normal wear and tear, misuse, use not for the intended purpose or not in accordance with the
product manual, abuse, accident, rental, modification or alteration, unauthorized repair, improper
installation, neglect, lack of maintenance, or any other failure not arising from defective materials or
workmanship. Fraudulent returns or claims will be denied. The repair or replacement described in this
warranty shall be your sole and exclusive remedy. THIS WARRANTY IS EXCLUSIVE AND IN LIEU
OF ALL OTHER EXPRESS WARRANTIES, WRITTEN OR ORAL, AND ANY IMPLIED WARRANTIES
ARE DISCLAIMED TO THE EXTENT PERMITTED BY LAW AND OTHERWISE LIMITED TO THE
DURATION OF THE EXPRESS WARRANTY HEREIN. HARBOR FREIGHT SHALL NOT BE LIABLE
UNDER ANY CIRCUMSTANCES FOR ANY INCIDENTAL, INDIRECT, SPECIAL, CONSEQUENTIAL,
OR PUNITIVE DAMAGES OR COSTS ARISING FROM THIS WARRANTY OR THE USE OF THIS
PRODUCT. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY
LASTS OR THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO
THESE LIMITATIONS MAY NOT APPLY TO YOU. THIS WARRANTY GIVES YOU SPECIFIC LEGAL
RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE.
®
For product assistance, visit harborfreight.com/customer-support/contact-us
Visit our website at: https://www.harborfreight.com
Copyright
©
2026 by Harbor Freight Tools
®
. All rights reserved. No portion of this manual or
any artwork contained herein may be reproduced in any shape or form without the express
written consent of Harbor Freight Tools. Diagrams within this manual may not be drawn
proportionally. Due to continuing improvements, actual product may differ slightly from the
product described herein. Tools required for assembly and service may not be included.
