DeWalt D28112 User manual

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iNSTRUCTiON MANUAL
GUIDE D'UTILISATION
MANUAL DE INSTRUCCIONES
INSTRUCTIVO DE OPERACION, CENTROS DE SERVICIO Y P©LIZA DE
GARANT[A. ADVERTENClA: LEASE ESTE INSTRUCTIVO ANTES DE
USAR EL PRODUCTO.
E ®
D28112, D28402, D28402N
Heavy-Duty Small Angle Grinder
Petites meuleuses angulaires de service intensif
Esmeriladoras angulares pequehas para trabajo pesado

Definitions: Safety Guidelines
The definitions below describe the level of severity for each
signal word, Please read the manual and pay attention to these
symbols.
ADANGER: Indicates an imminently hazardous situation
which, if not avoided, will result in death or serious injury.
AWARNING: Indicates a potentially hazardous situation
which, if not avoided, could result in death or serious injury.
ACAUTION: Indicates apotentially hazardous situation which,
if not avoided, may result in minor or moderate injury.
NOTICE: Indicates a practice not related to personal injury
which, if not avoided, may result in property damage. J
IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS OR
ANY DEWALT TOOL, CALL US TOLL FREE AT: 1-800-4-DEWALT
(1-800-433-9258}.
WARNING: To reduce the risk of injury, read the instruction
manual.
General Power Tool Safety Warnings
AWARNING!Readallsafetywarningsandallinstructions.
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.
1} WORK AREA SAFETY
a) Keep work area clean and well lit, Cluttered or dark areas
invite accidents.
b) 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.
c) Keep children and bystanders away while operating a
power tool Distractions can cause you to lose control
2} ELECTRICAL SAFETY
a) 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.
b) 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.
c) Do not expose power tools to rain or wet conditions.
Water entering a power too/will increase the risk of electric
shock.
d) 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.
e) 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 apowertool in adamp location is unavoidable,
use a ground fault circuit interrupter (GFCI) protected
supply. Use of a GFCI reduces the risk of electric shock.
3} PERSONAL SAFETY
a) Stay alert, watch what you are doing and use common
sense when operating apower 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.
b) 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.
c) 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.
d) 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.
e) 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 jewelry.
Keep your hair, clothing and gloves away from moving
parts. Loose clothes, jewelry or long hair can be caught in
moving parts.
g) 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.
4) POWER TOOL USE AND CARE
a) 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.
b) 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.
c) 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.
d) 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.
e) Maintain power tools. Check for misallgnment 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
g) 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.

5) SERVICE
a) Have your power tool serviced by a qualified repair
person using only identical replacement parts. This will
ensure that the safety of the power too/is maintained.
SAFETY iNSTRUCTiONS FOR
ALL OPERATIONS
Safety Warnings Common for Grinding,
Sandingj Wire Brushing, Polishing or
Abrasivej Cu_ing-Off Operations
a) This power tool is intended to function as a grinder,
sander, wire brush, polisher or cut-off tool Read all safety
warnings, instructions, illustrations and specifications
provided with this power tool Failure to follow a//instructions
listed below may result in electric shock, fire and/or serious
injury.
b) 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.
c) 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.
d) 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.
e) The arbor size of wheels, flanges, backing pads 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 too/wi//run out of
balance, vibrate excessively and may cause loss of control.
Do not use a damaged accessory. Before each use
inspect the accessory such as abrasive wheels for chips
and cracks, backing pad 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.
g) 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.
h) 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.
i) Hold power tool by insulated gripping surfaces only,
when performing an operation where the cutting
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 electrical shock.

j) Position the cord clear of the spinning accessory. /f you
lose control, the cord may be cut or snagged and your hand or
arm may be pulled into the spinning accessory.
k) 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
I) 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.
m) 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.
n) Do not operate the power tool near flammable materials.
Sparks could ignite these materials.
o) Do not use accessories that require liquid coolants.
Using water or other liquid coolants may result in electrocution
or shock.
Causes and Operator Prevention
of Kickback
Kickback is a sudden reaction to a pinched or snagged rotating
wheel, backing pad, 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 fomed in the
direction opposite of the accessory's rotation at the point of the
binding.
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 operatod 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:
a) Maintain a firm grip on the power tool and position your
body and arm to allow you to resist kickback forces.
Always use auxiliary handle, if provided, for maximum
control over kickback or torque reaction during start up.
The operator can control torque reaction or kickback forces, if
proper precautions are taken.
b) Never place your hand near the rotating accessory.
Accessory may kickback over your hand.
c) Do not position your body in the area where power tool
will move if kickback occurs. Kickback will propel the tool
in direction opposite to the wheel's movement at the point of
snagging.
d) 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.
e) Do not attach a saw chain woodcarving blade or toothed
saw blade. Such blades create frequent kickback and loss of
control
Safety Warnings Specific for Grinding and
Abrasive Cutting-Off Operations
a) 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.
b) 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. Theguard helps

toprotectoperatorfrombrokenwheelfragments,accidental
contactwithwheel,andsparksthatcouldigniteclothing.
c)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 fomes applied to these wheels may cause them to shatte_
d) Always use undamaged wheel flanges that are of 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.
e) Do not use worn down wheels from larger power tools.
Wheel intended for larger power tool is not suitable for the
higher speed of a smaller tool and may burst.
Additional Safety Warnings Specific for
_brasive Cutting-Off Operations
a) Do not "jam" the 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 binding of the wheel in the cut and
the possibility of kickback or wheel breakage.
b) Do not position your body in line with and behind the
rotating wheel When the wheel, at the point of operation, is
moving away from your body, the possible kickback may propel
the spinning wheel and the power tool directly at you.
c) When wheel is binding 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 binding.
d) Do not restart the cutting operation in the workpiece.
Let the wheel reach full speed and carefully reenter the
cut. The wheel may bind, walk up or kickback if the power tool
is restarted in the workpiece.
e) 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
Use extra caution when making a "pocket cut" into
existing walls or other blind areas. The protruding wheel
may cut gas or water pipes, electrical wiring or objects that can
cause kickback.
Safety Warnings Specific for Sanding
Operations
a) Do not use excessively oversized sanding disc paper.
Follow manufacturers recommendations, when selecting
sanding paper. Larger sanding paper extending beyond the
sanding pad presents a laceration hazard and may cause
snagging, tearing of the disc or kickback.
Safety Warnings Specific for Polishing
Operations
a) Do not allow any loose portion of the polishing bonnet
or its attachment strings to spin freely. Tuck away or
trim any loose attachment strings. Loose and spinning
attachment strings can entangle your fingers or snag on the
workpiece.

Safety Warnings Specific for Wire
Brushing Operations
a) 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.
b) If the use of a guard is recommended for wire brushing,
do not allow any interference of the wire wheel or brush
with the guard. Wire wheel or brush may expand in diameter
due to work load and centrifugal fomes.
Additional Safety Rules for Grinders
WARNING: The grinding wheel or accessory may loosen
during coast-down of the tool when shut off. if grinding wheel or
accessory loosens, it may dismount from the machine and may cause
serious personal injury.
•Use of accessories not specified in this manual is not
recommended and may be hazardous. Use of power boosters
that would cause the too/to be driven at speeds greater than its
rated speed constitutes misuse.
•Use clamps or anotherpractical way to secure and support
the workpiece to astable platform. Holding the work by hand
or against your body leaves it unstable and may lead to loss of
control
•Avoid bouncing the wheel or giving it rough treatment. Ifthis
occurs, stop the tool and inspect the wheel for cracks or flaws.
Always handle and store wheels in a careful manne_
Never cut into area that may contain electrical wiring or
piping. Serious injury may result.
•Do not operate this tool for long periods of time. Vibration
caused by the operating action of this too/may cause permanent
injury to fingers, hands, and arms. Use gloves to provide extra
cushion, take frequent rest periods, and limit daily time of use.
o
o
o
o
Do not use Type 11 (flaring cup) wheels on this tool Using
inappropriate accessories can result in injury.
Always use side handle. Tighten the handle securely. The
side handle should always be used to maintain control of the too/
at all times.
Air vents often cover moving parts and should be avoided.
Loose clothes, jewelry or long hair can be caught in moving parts.
An extension cord must have adequate wire size (AWG
or American Wire Gauge) for safety. The smaller the gauge
number of the wire, the greater the capacity of the cable, that is
16 gauge has more capacity than 18 gauge. An undersized cord
will cause a drop in line voltage resulting in loss of power and
overheating. When using more than one extension to make up the
total length, be sure each individual extension contains at least the
minimum wire size. The following table shows the correct size to
use depending on cord length and nameplate ampere rating. If in
doubt, use the next heavier gauge. Thesmaller the gauge numbed
the heavier the cord.
Ampere Rating
Minimum Gauge for Cord Sets
Total Length of Cord
Volts in Feet (meters)
120V 25 (7.6) 50 (15.2) 100 (30.5) 150 (45.7)
240V 50 (15.2) 100 (30.5) 200 (61.0) 300 (91.4)
More Not More AWG
Than Than
0 6 18 16 16 14
6 10 18 16 14 12
10 12 16 16 14 12
12 16 14 12 NotRecommended

i_,WARNING: ALWAYS use safety glasses. Everyday eyeglasses are
NOT safety glasses. Also use face or dust mask if cutting operation is
dusty. ALWAYS WEAR CERTIFIED SAFETY EQUIPMENT_
•ANSI Z87.1 eye protection (CAN/CSA Z94.3),
ANSI $12.6 ($3.19) hearing protection,
NIOSH/OSHA/MSHA respiratory protection.
i_WARNING: Some dust created by power sanding, sawing,
grinding, drilling, and other construction activities contains chemicals
known to the State of Califomia to cause canced birth defects or other
reproductive harm. Some examples of these chemicals are:
lead from lead-based paints,
crystalline silica from bricks and cement and other masonry
products, and
arsenic and chromium from chemically-treated lumbe_
Your risk from these exposures varies, depending on how often you
do thb type of work. To reduce your exposure to these chemicab:
work in a well ventilated area, and work with approved safety
equipment, such as those dust masks that are specially designed to
filter out microscopic particles.
Avoid prolonged contact with dust from power sanding,
sawing, grinding, drilling, and other construction activities.
Wear protective clothing and wash exposed areas with
soap and water. Allowing dust to get into your mouth, eyes, or
lay on the skin may promote absorption of harmful chemicals.
_, WARNING: Use of this tool can generate and/or disperse dust,
which may cause serious and permanent respiratory or other injury.
Always use NIOSH/OSHA approved respiratory protection appropriate
for the dust exposure. Direct particles away from face and body.
i_ WARNING: Always wear proper personal hearing protection
that conforms to ANSI $12.6 ($3.19) during use. Under some
conditions and duration of use, noise from this product may
contribute to hearing loss.
The label on your tool may include the following symbols. The
symbols and their definitions are as follows:
V................... volts
Hz................. hertz
min ............... minutes
.... or DC... direct current
_) ................. Class I Construction
(grounded)
A...................... amperes
W..................... watts
*or AC .......... alternating
current
or AC/DC... alternating or
direct current
[] ................. Class II Construction no .................... no load
(double insulated) speed
.../min .......... per minute n ...................... rated speed
BPM ............. beats per minute _ ..................... earthing
IPM ............... impacts per minute terminal
RPM ............. revolutions per _, ..................... safety alert
minute symbol
sfpm ............. surface feet per minute
SAVE THESE INSTRUCTIONS FOR
FUTURE USE

COMPONENTS (Fig. 1, 2)
_WARNING: Never modify the power tool or any part of it. Damage
or personal injury could result.
A. Paddle Switch
(D28402, D28402N)
B. Lock-Off Lever
C. Spindle Lock Button
D. Spindle (not shown)
E. Side Handle
F.4-1/2" (114.3 mm) Grinding
Wheel
G. Anti-Lockup Backing Flange
H. Threaded Clamp Nut
I. Guard
J. Lock On Button (D28402)
K. Dust Ejection System TM
(DES)
L. Slider Switch (D28112)
INTENDED USE
The D28112, D28402 and D28402N heavy-duty angle grinders have
been designed for professional grinding at various work sites (i.e.,
construction sites). DO NOT use under wet conditions or in presence
of flammable liquids or gases.
These heavy-duty angle grinders are professional power tools. DO
NOT let children come into contact with the tool. Supervision is
required when inexperienced operators use this tool.
ASSEMBLY AND ADJUSTMENTS
_WARNING: To reduce the risk of injury, turn unit off and
disconnect it from power source before installing and removing
accessories, before adjusting or when making repairs. Before
reconnecting the tool, depress and release the trigger switch
to ensure that the tool is off. An accidental start-up can cause
injury.
FIG. 1
D28402
D28402N
D28112
BJ
(D28402)

4-1/2 =' (114.3 rnm) Grinding Wheels Wire Wheels
Type 27 guard
backing flange
Type 27 depressed
center wheel
threaded clamp nut
ATTACHING SIDE HANDLE (FIG. 2)
The side handle (E)can be fitted to either
side of the gear case in the threaded
holes, as shown. Before using the tool,
check that the handle is tightened secure-
ly. Use a wrench to firmly tighten the side
handle.
Type 27 guard
Type 27 hubbed wheel
FIG.2
Type 27 guard
3" (76.2 mm)
wire cup brush
Type 27 guard
4" (101.6 mm)
wire wheel
Rotating the Gear Case (Fig. 3)
1. Remove guard and flanges from tool.
2. Remove the four corner screws attaching the gear case to motor
housing.
3. Separating the gear case from motor housing not more than 1/4"
(6.35 mm) rotate the gear case head to desired position.
NOTE: Ifthe gear case and motor housing FIG.3
become separated by more than 1/4"
(6.35 mm), the tool must be serviced and
re-assembled by a DE.:.WALTservice center.
Failureto have the tool serviced may cause
brush, motor and bearing failure. 90° 90°

4-1/2" (114.3 ram)
Cutting Wheels
Type 1 guard
backing flange
abrasive cutting wheel
threaded clamp nut
Type 1 guard
backing flange
diamond cutting wheel
threaded clamp nut
Sanding Discs
rubber backing pad
sanding disc
threaded clamp nut
4-1/2" (114.3 rnm)
Sanding Flap Discs
Type 27 guard
hubbed sanding
flap disc
Type 27 guard
backing flange
non-hubbed sanding
flap disc
threaded clamp nut
3.Re-install screws to attach the gear case to the motor housing.
Tighten screws to 18 in./Ibs, torque. Overtightening could cause
screws to strip.
Accessories
It is important to choose the correct guards, backing pads and
flanges to use with grinder accessories. See pages 9-10 for
information on choosing the correct accessories.
10
AWARNING: Accessories must be rated for at least the speed
recommended on the tool waming label. Wheelsand other accessories
running over rated accessory speed may burst and cause injury.
Threaded accessories must have a 5/8"-11 hub. Every unthreaded
accessory must have a 7/8" (22.2 mm) arbor hole. Ifit does not, it may
have been designed for a circular saw and should not be used. Use
only the accessories shown on pages 9-10 of this manual Accessory
ratings must be above listed minimum wheel speed as shown on tool
nameplate.

Mounting Guard
MOUNTING AND REMOVING GUARD (FIG. 4, 5)
i_ CAUTION: Guards must be used with all grinding wheels,
sanding flap discs, wire brushes, and wire wheels. The tool may
be used without a guard only when sanding with conventional
sanding discs. Some DFWALT models are provided with a guard
intended for use with depressed center wheels (Type 27) and hubbed
grinding wheels (Type27). The same guard is designed for use with
sanding flap discs (Type 27 and 29) and wire brushes. Grinding and
cutting with wheels other than Type 27 and 29 require different
accessory guards not included with tool. Mounting instructions for
these accessory guards are included in the accessory package.
1. Open the guard latch (M). Align the lugs (N) on the guard with the
slots (O)on the gear case.
FIG. 4 N
2. Push the guard down until the guard lugs engage and rotate freely
in the groove on the gear case hub.
3. With the guard latch open, rotate the guard (I) into the desired
working position. The guard body should be positioned
between the spindle and the operator to provide maximum
operator protection.
4. Close the guard latch to secure the guard on the gear case. You
should not be able to rotate the guard by hand when the latch
is closed. Do not operate the grinder with a loose guard or the
clamp lever in open position.
5. To remove the guard, open the guard latch, rotate the guard so
that the arrows are aligned and pull up on the guard.
NOTE: The guard is pre-adjusted to the FIG.5
diameter of the gear case hub at the factory.
If, after a period of time, the guard becomes
loose, tighten the adjusting screw (P) with
clamp lever in the closed position.
A CAUTION: Do not tighten the adjusting screw with the clamp lever
in open position. Undetectable damage to the guard or the mounting
hub may result.
i_,CAUTION: If guard cannot be tightened by adjusting clamp, do
not use tool and take the tool and guard to a service center to repair
or replace the guard.
OPERATION
AWARNING: To reduce the risk of injury, turn unit off and
disconnect ff from power source before installing and removing
accessories, before adjusting or when making repairs. Before
reconnecting the tool, depress and release the trigger switch
to ensure that the tool is off. An accidental start-up can cause
injury.
Guards and Flanges
It is important to choose the correct guards and flanges to use with
the grinder accessories. See pages 9-10 and this page for the correct
accessories.
NOTE: Edge grinding and cutting can be performed with Type 27
wheels designed and specified for this purpose.
11

,_ WARNING:Accessories must be rated for atleast the speed recom-
mended on the tool warning label. Wheels and other accessories
running over rated accessory speed may burst and cause injury.
Every unthreaded accessory must have a 7/8" (22.2 mm) arbor
hole. If it does not, it may have been designed for a circular saw and
should not be used. Use only the accessories shown on pages 9-10.
Accessory ratings must be above listed minimum wheel speed as
shown on tool nameplate.
Switches
ACAUTION: Hold the side handle and body of the tool firmly to
maintain control of the tool at start up and during use and until the
wheel or accessory stops rotating. Make sure the wheel has come to
a complete stop before laying the tool down.
NOTE: To reduce unexpected tool movement, do not switch the
tool on or off while under load conditions. Allow the grinder to run
up to full speed before touching the work surface. Lift the tool from
the surface before turning the tool off. Allow the tool to stop rotating
before putting it down.
PADDLE SWITCH (FIG. 1, 6}
D28402, D28402N
ACAUTION: Before connecting the tool to a power source depress
and release the paddle switch (A)once [D28402: without depressing
the lock-on button (J)] to ensure that the switch is off. Depress and
release the paddle switch as described above after any interruption in
power supply to the tool, such as the activation of a ground fault
interrupted throwing of a circuit breaked accidental unplugging, or
power failure. If the paddle switch is locked on, the tool will start
unexpectedly when it is reconnected.
To turn the tool on, push the lock-off FIG.6
lever (B) toward the back of the tool,
then depress the paddle switch (A).
The tool will run while the switch is
depressed. Turn the tool off by A B
releasing the paddle switch.
AWARNING: Do not disable the lock-off leve_ If the lock-off lever is
disabled, the tool may start unexpectedly when it is laid down.
SLIDER SWITCH (FIG. 7}
D28112
CAUTION: Before connecting the tool to a power supply, be sure
the switch is in the off.position by pressing the rear part of the switch
and releasing. Ensure the switch is in the off. position as described
above after any interruption in power supply to the tool, such as the
activation of a ground fault interrupte_ throwing of a circuit breake_
accidental unplugging, or power failure. If the switch is locked on when
the power is connected, the tool will start unexpectedly.
To start the tool, slide the ON/OFF FIG.7
switch (L)toward the front of the tool.
To stop the tool, release the ON/OFF
switch.
For continuous operation, slide the
switch toward the front of the tool L
and press the forward part of the
switch inward. To stop the tool while
operating in continuous mode, press
the rear part of the switch and release.
12

LOCK-ON BUTTON (FIG. 8}
D28402
The lock-on button (J) offers increased
comfort in extended use applications. To
lock the tool on, push the lock-off lever
(B) toward the back of the tool then
depress the paddle switch (A). With the
tool running, depress the lock-on button
(J).The tool will continue to run after the
paddle switch is released. To unlock the tool, depress and release the
paddle switch. This will cause the tool to stop.
ACAUTION: Allow the tool to reach full speed before touching tool
to the work surface. Lift the tool from the work surface before turning
the tool off.
SPINDLE LOCK (FIG. 9)
The spindle lock (C) is provided to prevent FIG.9
the spindle from rotating when installing or O
removing wheels. Operate the spindle lock
only when the tool is turned off, unplugged
from the power supply, and has come to a
complete stop. Do not engage the spindle
lock while the tool is operating because
damage to the tool will result. To engage the
lock, depress the spindle lock button and
rotate the spindle until you are unable to rotate the spindle further.
Mounting and Using Depressed Center
Grinding Wheels and Sanding Flap Discs
MOUNTING AND REMOVING HUBBED WHEELS
Hubbed wheels install directly on the 5/8"-11 threaded spindle.
Thread of accessory must match thread of spindle.
1. Backing flange is retained to the grinder by an O-ring on the
spindle. Remove backing flange by pulling and twisting flange
away form the machine.
2. Thread the wheel on the spindle by hand.
3. Depress the spindle lock button and use a wrench to tighten the
hub of the wheel.
4. Reverse the above procedure to remove the wheel.
ACAUTION: Failure to properly seat the wheel before turning the
tool on may result in damage to the tool or the wheel
MOUNTING NON-HUBBED WHEELS (FIG. 10, 11}
Depressed center Type 27 grinding wheels must be used with
included flanges. See page 9 of this manual for more information.
1. Install the unthreaded backing flange (G) on spindle (D) with the
raised section (pilot) against the wheel. Be sure the backing flange
recess is seated onto the flats of the spindle by pushing and
twisting the flange before placing wheel.
FIG.10
2. Place wheel against the backing flange, centering the wheel on
the raised section (pilot) of the backing flange.
3. While depressing the spindle lock button, thread the clamp nut
(H) on spindle. If the wheel you are installing is more than 1/8"
(3.17 mm) thick, place the threaded clamp nut on the spindle so
that the raised section (pilot) fits into the center of the wheel. If
the wheel you are installing is 1/8" (3.17 mm) thick or less, place
13

thethreadedclampnutonthespindlesothattheraisedsection
(pilot)isnotagainstthewheel.
4.Whiledepressingthespindlelockbutton,tightentheclampnut
withawrench.
5.Toremovethewheel,depressthespindlelockbuttonandloosen
thethreadedclampnutwithawrench.
NOTE:Ifthewheelspinsaftertheclampnutistightened,checkthe
orientationofthethreadedclampnut.Ifathinwheelisinstalledwith
thepilotontheclampnutagainstthewheel,itwillspinbecausethe
heightofthepilotpreventstheclampnutfromholdingthewheel.
FIG.11 1/4"(6.35mm) 1/8"(3.17mm)
WHEELS WHEELS
CLAMP NUT CLAMP NUT
BACKINGFLANGE BACKING FLANGE
SURFACE GRINDING WITH GRINDING WHEELS (FIG. 12)
1. Allow the tool to reach full speed before touching the tool to the
work surface.
2. Apply minimum pressure to the FIG.12 ...........
work surface, allowing the tool to ':
operate at high speed. Grinding _0o_30°
rate is greatest when the tool
operates at high speed.
3. Maintain a 20°to 30°angle between the tool and work surface.
4. Continuously move the tool in a forward and back motion to avoid
creating gouges in the work surface.
5. Remove the tool from work surface before turning tool off. Allow
the tool to stop rotating before laying it down.
EDGE GRINDING WITH GRINDING WHEELS (FIG, 13)
_CAUTION." Wheels used for cutting and edge grinding may break if
they bend or twist while the tool is being used to do cut-off work or
deep grinding. Toreduce the riskof serious injury, limit the use of these
wheels with a standard Type 27 guard to shallow cutting and notching
(less than 1/2" in depth). The open side of the guard must be
positioned away from the operato_ For deeper cutting with a Type 1
cut-off wheel, use a closed, Type 1 guard. See the chart on page 10
for more information. Type 1guards are available at extra cost from
your local dealer or authorized service cente_
1. Allow the tool to reach full speed FIG.13
before touching the tool to the work
surface. __
2. Apply minimum pressure to the
work surface, allowing the tool to
operate at high speed. Grinding rate
is greatest when the tool operates ......,.<_¢_
at high speed.
3. Position yourself so that the open-
underside of the wheel is facing
away from you.
4. Once a cut is begun and a notch is
established in the workpiece, do not
5,
change the angle of the cut. Changing the angle will cause the
wheel to bend and may cause wheel breakage. Edge grinding
wheels are not designed to withstand side pressures caused by
bending.
Remove the tool from the work surface before turning the tool off.
Allow the tool to stop rotating before laying it down.
14

,_,WARNING: Do not use edge grinding/cutting wheels for surface
grinding applications because these wheels are not designed for side
pressures encountered with surface grinding. Wheel breakage and
injury may result.
SURFACE FINISHING WITH SANDING FLAP DISCS (FIG. 14}
1. Allow the tool to reach full speed FIG.34
before touching the tool to the
work surface.
2. Apply minimum pressure to work
surface, allowing the tool to
operate at high speed. Sanding
rate is greatest when the tool operates at high speed.
3. Maintain a 5° to 10° angle between the tool and work surface.
4. Continuously move the tool in a forward and back motion to
avoid creating gouges in the work surface.
5. Remove the tool from work surface before turning tool off. Allow
the tool to stop rotating before laying it down.
MOUNTING SANDING BACKING PADS {FIG. 15}
ACAUTION: Proper guard must be reinstalled for grinding wheel,
sanding flap disc, wire brash or wire wheel applications after sanding
applications are complete. FIG.15 H R
1. Place or appropriately thread
backing pad (Q) on the
spindle. :
2. Place the sanding disc (R)on
the backing pad.
Q
15
3. While depressing spindle lock, thread clamp nut (H) on spindle,
piloting the raised hub on the clamp nut into the center of sanding
disc and backing pad.
4. Tighten the clamp nut by hand. Then depress the spindle lock
button while turning the sanding disc until the sanding disc and
clamp nut are snug.
5. To remove the wheel, grasp and turn the backing pad and
sanding pad while depressing the spindle lock button.
USING SANDING BACKING PADS (FIG. 16}
Choose the proper grit sandpaper for your application. Sandpaper
is available in various grits. Coarse grits yield faster material removal
rates and a rougher finish. Finer grits yield slower material removal
and a smoother finish.
Begin with coarse grit discs for fast, rough material removal. Move
to a medium grit paper and finish with a fine grit disc for optimal
finish. Coarse 16 - 30 grit
Medium 36 - 80 grit
Fine Finishing 100 - 120 grit
Very Fine Finishing 150 - 180 grit
1. Allow the tool to reach full speed FIG.16
before touching tool to the work
surface.
2. Apply minimum pressure to work ......
5o_15o
surface, allowing the tool to
operate at high speed. Sanding
rate is greatest when the tool
operates at high speed.
3, Maintain a 5° to 15° angle between the tool and work surface.
The sanding disc should contact approximately one inch of work
surface.

4.Movethetoolconstantlyinastraightlinetopreventburningand
swirlingofworksurface.Allowingthetooltorestonthework
surfacewithoutmoving,ormovingthetoolinacircularmotion
causesburningandswirlingmarksontheworksurface.
5.Removethetoolfromworksurfacebeforeturningtooloff.Allow
thetooltostoprotatingbeforelayingitdown.
Mounting and Using Wire Brushes
and Wire Wheels
Wire cup brushes or wire wheels screw directly on the grinder
spindle without the use of flanges. Use only wire brushes or wheels
provided with a 5/8"-11 threaded hub. A Type 27 guard is required
when using wire brushes and wheels.
CAUTION: Wear work gloves when handling wire brushes
and wheels. They can become sharp.
ACAUTION: Wheel or brash must not touch guard when mounted
or while in use. Undetectable damage could occur to the accessory,
causing wires to fragment from accessory wheel or cup.
MOUNTING WIRE CUP BRUSHES AND WIRE WHEELS
1. Thread the wheel on the spindle by hand.
2. Depress spindle lock button and use a wrench on the hub of the
wire wheel or brush to tighten the wheel.
3. To remove the wheel, reverse the above procedure.
CAUTION." Failure to properly seat the wheel hub before turning
the tool on may result in damage to tool or wheel.
USING WIRE CUP BRUSHES AND WIRE WHEELS
(FIG. 17, 18}
Wire wheels and brushes can be used for removing rust, scale and
paint, and for smoothing irregular surfaces.
1. Allow the tool to reach full speed before touching the tool to the
work surface.
2. Apply minimum pressure to work surface, allowing the tool to
operate at high speed. Material removal rate is greatest when the
tool operates at high speed.
3. Maintain a 5°to 10°angle between the tool and work surface for
wire cup brushes.
4. Maintain contact between the edge of the wheel and the work
surface with wire wheels.
FIG. 17 FIG. 18
5. Continuously move the tool in a forward and back motion to avoid
creating gouges in the work surface. Allowing the tool to rest on
the work surface without moving, or moving the tool in a circular
motion causes burning and swirling marks on the work surface.
6. Remove the tool from the work surface before turning the tool off.
Allow the tool to stop rotating before setting it down.
h_CAUTION: Use extra care when working over an edge, as a
sudden sharp movement of grinder may be experienced.
Mounting and Using Cutting
(Type 1) Wheels
Cutting wheels include diamond wheels and abrasive discs. Abrasive
cutting wheels for metal and concrete use are available. Diamond
blades for concrete cutting can also be used.
16

i_WARNING: A closed, 2-sided cutting wheel guard is not included
with this tool but is required when using cutting wheels. Failure to use
proper flange and guard can result in injury resulting from wheel
breakage and wheel contact. See page 9 for more information.
MOUNTING CLOSED (TYPE 1) GUARD (FIG. 19, 20)
1. Open the guard latch (M). Align the lugs (N) on the guard with the
slots (O)on the gear case.
FIG. 19 O
N
2. Push the guard down until the guard lug engages and rotates
freely in the groove on the gear case hub.
3. Rotate guard (I)into desired working position. The guard body
should be positioned between thespindle and the operator to
provide maximum operator protection.
4. Close the guard latch to secure the FIG.20
guard on the gear case cover. You
should be unable to rotate the guard
by hand when the latch is in closed
position. If rotation is possible, tighten
the adjusting screw (P) with clamp
lever in the closed position. Do not
operate grinder with a loose guard or clamp lever in open
position.
5. To remove the guard, open the guard latch, rotate the guard so
that the arrows are aligned and pull up on the guard.
NOTE: If,after a period of time, the guard becomes loose, tighten the
adjusting screw (P)with the clamp lever in the closed position.
ACAUTION: Do not tighten adjusting screw with clamp leverin open
position. Undetectable damage to guard or mounting hub may result.
MOUNTING CUTTING WHEELS
ACAUTION: Matching diameter threaded backing flange and clamp
nut (included with tool) must be used for cutting wheels.
1. Place the unthreaded backing flange on spindle with the raised
section (pilot) facing up. The raised section (pilot) on the backing
flange will be against the wheel when the wheel is installed.
2. Place the wheel on the backing flange, centering the wheel on the
raised section (pilot).
3. Install the threaded clamp nut with the raised section (pilot)
facing away from the wheel.
4. Depress the spindle lock button and tighten clamp nut with a
wrench.
5. To remove the wheel, grasp and turn while depressing the
spindle lock button.
USING CUTTING WHEELS (FIG. 21}
i_ WARNING: Do not use edge grinding/cutting wheels for surface
grinding applications because these wheels are not designed for side
pressures encountered with surface grinding. Wheel breakage and
injury may result.
17

1.Allowtoolto reachfullspeed FIG.21
beforetouchingtool to work
surface.
2.Applyminimumpressuretowork
surface,allowingtooltooperate
at highspeed.Cuttingrateis
greatestwhenthetooloperates
athighspeed.
3.Onceacutisbegunandanotch
isestablishedintheworkpiece,
donotchangetheangleofthe
cut.Changingtheanglewillcause
thewheeltobendandmaycause
wheelbreakage.
4.Removethetoolfromworksurfacebeforeturningtooloff.Allow
thetooltostoprotatingbeforesettingitdown.
MAINT£NANCE
AWARNING: To reduce the risk of injury, turn unit off and
disconnect it from power source before installing and removing
accessories, before adjusting or when making repairs. Before
reconnecting the tool, depress and release the trigger switch
to ensure that the tool is off. An accidental start-up can cause
injury.
Cleaning
AWARNING: Blow dirt and dust out of allair vents with clean, dry air
at least once a week. To minimize the risk of eye injury, always wear
ANSI Z87.1 approved eye protection when performing this.
i_,WARNING: Never use solvents or other harsh chemicals for
cleaning the non-metallic parts of the tool. These chemicals may
weaken the plastic materials used in these parts. Use a cloth
dampened only with water and mild soap. Never let any liquid get
inside the tool,"never immerse any part of the tool into a liquid.
Accessories
_WARNING: Since accessories, other than those offered by
D_-/WALT,have not been tested with this product, use of such
accessories with this tool could be hazardous. Toreduce the risk of
injury, only D,£WALTrecommended accessories should be used with
this product.
Recommended accessories for use with your tool are available at
extra cost from your local dealer or authorized service center. If you
need assistance in locating any accessory, please contact DEWALT
Industrial Tool Co., 701 East Joppa Road, Baltimore, MD 21286,
call 1-800-4-DL:.WALT (1-800-433-9258) or visit our website: www.
dewalt.com.
Repairs
To assure product SAFETY and RELIABILITY, repairs, maintenance
and adjustment (including brush inspection and replacement) should
be performed by a DEiWALT factory service center, a DEWALT
authorized service center or other qualified service personnel. Always
use identical replacement parts.
Register Online
Thank you for your purchase. Register your product now for:
,WARRANTY SERVICE: Registering your product will help you
obtain more efficient warranty service in case there is a problem
with your product.
18

,,CONFIRMATIONOFOWNERSHIP:Incaseofaninsurance
loss,suchasfire,floodortheft,yourregistrationofownershipwill
serveasyourproofofpurchase.
•FOR YOUR SAFETY: Registering your product will allow us to
contact you in the unlikely event a safety notification is required
under the Federal Consumer Safety Act.
Register online at www.dewalt.com/register.
Three Year Limited Warranty
DE.:.WALTwill repair,without charge, any defects due to faulty materials
or workmanship for three years from the date of purchase. This
warranty does not cover part failure due to normal wear or tool
abuse. For further detail of warranty coverage and warranty repair
information, visit www.dewalt.com or call 1-800-4-DEWALT (1-800-
433-9258). This warranty does not apply to accessories or damage
caused where repairs have been made or attempted by others. This
warranty gives you specific legal rights and you may have other rights
which vary in certain states or provinces.
In addition to the warranty, DE.:.WALTtools are covered by our:
1 YEAR FREE SERVICE
DEWALT will maintain the tool and replace worn parts caused by
normal use, for free, any time during the first year after purchase.
90 DAY MONEY BACK GUARANTEE
If you are not completely satisfied with the performance of your
DE.:.WALTPower Tool, Laser, or Nailer for any reason, you can return
it within 90 days from the date of purchase with a receipt for a full
refund - no questions asked.
LATIN AMERICA: This warranty does not apply to products sold
in Latin America. For products sold in Latin America, see country
specific warranty information contained in the packaging, call the local
company or see website for warranty information.
FREE WARNING LABEL REPLACEMENT: If your warning labels
become illegible or are missing, call 1-800-4-DE.:.WALT(1-800-433-
9258) for a free replacement.
19