DeWalt DWE4120N TYPE 1, DWE4120 TYPE 1 Owner’s Manual

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INSTRUCTION MANUAL
GUIDE D'UTILISATION
MANUAL DE INSTRUCCIONES

DWE4100, DWE4120, DWE4120N

Small Angle Grinder

Petite meuleuse angulaire
Esmeriladora angular pequeha

INSTRUCTIVO DE OPERACION, CENTROS DE SERVICIO Y POLIZA DE
GARANT[A. ADVERTENOIA: LEASE ESTE INSTRUCTIVO ANTES DE

USAR EL PRODUCTO.

®

Definitions: Safety Guidelines

The definitions below describe the level of severity br each

signal word. Please read the manual and pay attention to these
symbols.

_DANGER: Indicates an imminently hazardous situation

which, if not avoided, will result in death or serious injury.

_ WARNING: Indicates a potentially hazardous situation which,
if not avoided, could result in death or serious injury.

A CAUTION: Indicates a potentially 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.

IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS OR

ANY DF:WALTTOOL, CALL US TOLL FREE AT: 1-800-4-DEWALT

(1-800-433-9258).

_ ARNING: To reduce the risk of injury, read the instruction

manual.

General Power Tool Safety Warnings

_ WARNING! Read all safety warnings and all 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

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 tool 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 a damp location is unavoidable,
use a ground fault circuit interrupter (GFCI) protected
supply. Use of a GFC/ reduces the risk of electric shock.

3) PERSONAL SAFETY

a) 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.

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.

f) 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 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

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 tool is maintained.

SAFETY INSTRUCTIONS FOR

ALL OPERATIONS

Safety Warnings Common for Grinding,
Sanding, Wire Brushing, Polishing or

Abrasive, Cutting-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 all 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 tool will run out of balance,
vibrate excessively and may cause loss of control

f) 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 shock the operator.

j) 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.

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.

Kickback and Related Warnings

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 forced 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 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:

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. Comers,
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. The

guard helps to protect operator from broken wheel fragments,
accidental contact with wheel, and sparks that could ignite

clothing.

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 forces applied to these wheels may cause them to shatter.

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
Abrasive 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

Op era tions

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
Op era tions:

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 tool to be driven at speeds greater than its
rated speed constitutes misuse.

• Use clamps or anotherpractical way to secure and support
the workpiece to a stable 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 manner.

• 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 tool 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.

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 tool
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. The smaller the gauge number,
the heavier the cord.

Minimum Gauge for Cord Sets

Volts

Ampere Rating

More Not More
Than Than

0 6 18 16 16 14

6 10 18 16 14 12
10 12 16 16 14 12
12 16 14 12 Not Recommended

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)

Total Length of Cord

in Feet (meters)

AWG

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 CERTIFIEDSAFETY 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 California to cause cancer, 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 lumber.

Your risk from these exposures varies, depending on how often you
do thb type of work. To reduce your exposure to these chemicals:

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 useNIOSH/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

.................. minutes

- -- or DC... direct current

_) ................. Class I Construction

(grounded)

[] ................. 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

A...................... amperes

W..................... watts

,x,or AC ..........alternating

current

or AC/DC... alternating or

direct current

SAVE THESE INSTRUCTIONS FOR

FUTURE USE

Motor

Be sure your power supply agrees with the nameplate marking.
Voltage decrease of more than 10% will cause loss of power and
overheating. DEWALT tools are factory tested; if this tool does not
operate, check power supply.

COMPONENTS (Fig. 1, 6)

_ WARNING: Never modify the power tool or any part of it. Damage
or personal injury could result.

A. Spindle lock button G. Slider switch
B. Spindle H. Paddle switch

C. Side handle I. Lock on Button
D. Backing flange J. Lock off lever (Fig. 6)

E. Threaded clamp nut K. Guard release lever

F.Guard

INTENDED USE

This grinder isdesigned for professional grinder, sander, wire brush or

cut-off applications.
DO NOT use under wet conditions or in presence of flammable

liquids or gases.

This grinder is a professional power tool. 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. An

accidental start-up can cause injury.

FIG. 1

DWE4100

DWE4120

DWE4120N

4-1/2" (114.3 mnl

Grinding Wheels

Wire Wheels

Type 27 guard

backing flange

Type 27 hubbed wheel

Type 27 depressed

center wheel

threaded clamp nut

ATTACHING SIDE HANDLE (FIG. 2)

The side handle (C)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 securely. Use a wrench to firmly
tighten the side handle.

Type 27 guard

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 the four corner screws
attaching the gear case to motor

housing.

2. Without separating the gear case from
motor housing, rotate the gear case
head to desired position.

NOTE" If the gear case and motor housing become separated

by more than 1/8" (3.17 mm), the tool must be serviced and
re-assembled by a DEWALT service center. Failure to have the tool

serviced may cause brush, motor and bearing failure.

3. Reinstall screws to attach the gear case to the motor housing.

Tighten screws to 18 in.-Ibs, torque. Overtightening could cause

screws to strip.

4-1/2" (114.3 mm

Type 1 guard

Cutting Wheels

Type 1guard

Sanding Discs

rubber backing pad

4-1/2" (114.3 mm) Sanding Flap Discs

Type 27 guard

Type 27 guard

backing flange

abrasive cutting wheel

clamp nut

backing flange

diamond cutting wheel

clamp nut

sanding disc

threaded clamp nut

Accessories and Attachments

It isimportant 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.

_, WARNING: Accessories must be rated for at least the speed

recommended on the tool warning label Wheels and 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" arbor hole. If it does not, it

may have been designed for a circular saw and should not be used.

backing flange

hubbed sanding

flap disc

non-hubbed sanding

flap disc

threaded clamp nut

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

i_ CAUTION: Guards must be used with all grinding wheels,
cutting wheels, sanding flap discs, wire brushes, and wire
wheels. The tool may be used without a guard only when sanding

with conventional sanding discs. A Type 27 guard (intended for use
with depressed center grinding wheels [Type27 and Type29], sanding

flap discs, wire wheels and wire cup brushes) is available at extra cost

10

from your local dealer or authorized service center. Grinding and
cutting with wheels other than Type 27 and 29 require different

accessory guards not included with tool. A Type 1 guard is provided
for use with the Type 1 wheel. Mounting instructions for accessory
guards are shown below and are also included in the accessory
package.

MOUNTING AND REMOVING (TYPE 27)
ONE-TOUCH TM GUARD (FIG. 4, 5) FIG 4

NOTE: If your grinder is supplied with a

keyless ONE TOUCH TM guard, ensure the
screw, lever and spring are fitted correctly
before mounting the guard.

1. Press the guard release lever (K).

2. While holding the guard release lever open,
align the lugs (L) on the guard with the

slots on the gear case (M).

3. Keeping the guard release lever open, push the guard down until
the guard lugs engage and rotate them in the groove on the gear

case hub. Release the guard release lever.

4. With the spindle facing the operator, rotate FIG.5
the guard clockwise into the desired
working position. The guard body should
be positioned between the spindle and
the operator to provide maximum operator
protection.

5. For easy adjustment, the guard can be
rotated in the clockwise direction. NOTE"

The guard release lever should snap into

one of the alignment holes (N) on the
guard collar. This insures that the guard is secure. The guard can
be repositioned the opposite direction by depressing the guard

release lever.

6. To remove the guard, follow steps 1-3 of these instructions in
reverse.

NOTE" Edge grinding and cutting can be performed with Type 27
wheels designed and specified for this purpose; 1/4" (6.35 ram) thick
wheels are designed for surface grinding while 1/8" (3.17 ram) wheels
are designed for edge grinding. Cutting can also be performed by
using a Type 1 wheel and a Type 1 guard.

OPERATION

i_ 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. 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 page 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.

i_,WARNING: Accessories must be rated for at least the speed

recommended 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" 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

A CAUTION: 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.

11

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 (DWE4120, DWE4120N) (FIG. 6)

A CAUTION: Before connecting the tool to apower source depress
and release the paddle switch (H) 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 interrupter, throwing of a circuit breaker, accidental
unplugging, or power failure.

To turn the tool on, push the lock-off FIG.6

lever (J) toward the back of the tool,
then depress the paddle switch (H).

The tool will run while the switch is

depressed. Turn the tool off by H
releasing the paddle switch. J

WARNING: Do not disable the Iock-off lever. If the Iock-off lever is

disabled, the tool may start unexpectedly when it is laid down.

SLIDER SWITCH (FIG. 7) FIG.7
_t,WARNING: Before connecting the

tool to a power supply, be sure the
slider switch is in the off position by
pressing the rear part of the switch

and releasing. Ensure the slider switch G
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 interrupter,
throwing of a circuit breaker, accidental unplugging, or power failure.
Ifthe slider switch is locked on when the power is connected, the tool
will start unexpectedly,

To start the tool, slide the ON/OFF slider switch (G)toward the front of

the tool. To stop the tool, release the ON/OFF slider switch.

For continuous operation, slide the switch toward the front of the
tool and press the forward part of the switch inward. To stop the tool
while operating in continuous mode, press the rear part of the slider

switch and release.

LOCK-ON BUTTON (DWE4120) (FIG. 8}

The lock-on button (I) offers increased comfort in extended use

applications. To lock the tool on, push the FIG.8
lock-off lever (J) toward the back of the
tool then depress the paddle switch (H).

With the tool running, depress the lock-
on button (I).The tool will continue to run

after the paddle switch is released. To
unlock the tool, depress and release the H j I

paddle switch. This will cause the tool to
stop.

i_ CAUTION: 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 button (A) is provided to FIG.9

prevent the spindle from rotating when
installing or 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 button 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.

12

A

Mounting and Using Depressed Center
Grinding Wheels and Sanding Flap Discs

MOUNTING AND REMOVING HUBBED WHEELS (FIG. 10)

Hubbed wheels install directly on the 5/8"-11 FIG.10
threaded spindle. Thread of accessory must D

match thread of spindle.

1. Remove backing flange (D) by pulling B
away from the tool.

2. Thread the wheel on the spindle (B) 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. E_

NOTICE: Failure to properly seat the wheel
betore turning the tool on may result in 1/4" WHEELS

damage to the tool or the wheel (6.35mm)

MOUNTING NON-HUBBED WHEELS
(FIG. 10} OlampNut

Depressed center Type 27 grinding wheels
must be used with included flanges. Refer
to Accessories and Attachments for more

information.

1. Installthe backing flange (D)on spindle (B)
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.

Backing Flange

1/8" WHEELS

(3.17 mm)

Clamp Nut

Backing Flange

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 (E)on spindle. Ifthe 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
the threaded clamp nut on the spindle so that the raised section
(pilot) is not against the wheel.

4. While depressing the spindle lock button, tighten the clamp nut
with a wrench.

5. To remove the wheel, depress the spindle lock button and loosen
the threaded clamp nut with a wrench.

NOTE: If the wheel spins after the clamp nut is tightened, check the
orientation of the threaded clamp nut. If a thin wheel is installed with
the pilot on the clamp nut against the wheel, it will spin because the
height of the pilot prevents the clamp nut from holding the wheel.

SURFACE GRINDING WITH GRINDING WHEELS (FIG. 11)

1. Allow the tool to reach full speed 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. 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.

13

EDGE GRINDING WITH GRINDING WHEELS (FIG. 12)

_ WARNING: 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. To reduce the risk of 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 operator. For deeper cutting with a

Type 1 cut-off wheel, use a closed, Type 1 guard. See the chart on

pages 9-10 for more information. Type 1 guards are available at

extra cost from your local dealer or authorized service center.

1. Allow the tool to reach full speed before touching the tool to the
work surface.

2. Apply minimum pressure to the work FIG.12
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
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.

5. Remove the tool from the work surface before turning the tool off.

Allow the tool to stop rotating before laying it down.

A 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. 13)

3. 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. 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. 14}

A WARNING: Proper guard must be FIG. 14 P
reinstalled for grinding wheel, sanding flap
disc, wire brush or wire wheel applications
after sanding applications are complete.

1. Place or appropriately thread backing
pad (O) on the spindle.

2. Place the sanding disc (P) on the
backing pad.

3. While depressing spindle lock, thread
the clamp nut (E) on spindle, piloting
the raised hub on the clamp nut into
the center of sanding disc and backing
pad.

14

4.Tightentheclampnutbyhand.Thendepressthespindlelock
buttonwhileturningthesandingdiscuntilthesandingdiscand
clampnutaresnug.

5.Toremovethewheel,graspandturnthebackingpadand
sandingpadwhiledepressingthespindlelockbutton.

USING SANDING BACKING PADS (FIG. 15)

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 before touching tool to the work
surface.

2. Apply minimum pressure to work FIG.15
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 5_15°
disc should contact approximately

one inch of work surface.

4. Move the tool constantly in a straight line to prevent burning and
swirling of 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.

5. Remove the tool from work surface before turning tool off. Allow
the tool to stop rotating before laying it down.

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.

A CAUTION: Wheel or brush 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.

NOTICE: 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 16, 17)

Wire wheels and brushes can be used for removing rust, scale and
paint, and for smoothing irregular surfaces.

15

1.AllowthetooltoreachfullspeedbeforeFIG.16
touchingthetooltotheworksurface.

2.Applyminimumpressuretoworksurface,
allowingthetoolto operateat high
speed.Materialremovalrateisgreatest
whenthetooloperatesathighspeed.

3.Maintaina5°to10°anglebetweenthetoolandworksurfacefor
wirecupbrushes.

4.Maintaincontactbetweentheedgeofthewheelandthework
surfacewithwirewheels.

5.Continuouslymovethetoolinaforwardand FIG.17
backmotiontoavoidcreatinggougesinthe
worksurface.Allowingthetooltorestonthe
worksurfacewithoutmoving,ormovingthe
toolinacircularmotioncausesburningand

swirlingmarksontheworksurface.

6.Removethetoolfromtheworksurfacebeforeturningthetooloff.

Allowthetooltostoprotatingbeforesettingitdown.

,_ 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.
A 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 10 for more information.

MOUNTING CLOSED (TYPE 1) GUARD (FIG. 18-20)

_ WARNING: If present, the ONE TOUCHTM guard screw, lever and
spring must be removed before attempting to mount the closed

(Type 1) guard. The removed parts must be retained and reinstalled
to use the ONE TOUCHTM guard. Noting the position of these parts
before disassembly will aid in reassembly.

1. Open the guard latch (Q). Align the FIG.18
lugs (L) on the guard with the slots

(M) on the gear case. M

2. Push the guard down until the guard
lug engages and rotates freely in

the groove on the gear case hub.

3. Rotate guard (F) into desired
working position. The guard body

should be positioned between the L
spindle and the operator to provide Q
nlaximum operator protection.

4. Close the guard latch to secure the FIG.19
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 (R)with clamp lever
in the closed position. Do not operate F

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.

16

NOTE: If, after a period of time the closed (Type 1) FIG.20
guard becomes loose, tighten the adjusting
screw (R) with the clamp lever in the closed R
position.

NOTICE: Do not tighten adjusting screw with
clamp lever in open position. Undetectable
damage to guard or mounting hub may result.

CAUTION: If the guard cannot be tightened by the adjusting clamp,

do not use the tool To reduce the risk of personal injury, take the tool
and guard to an authorized service center to repair or replace the

guard.

MOUNTING CUTTING WHEELS

A CAUTION: 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)

_, 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.

1. Allow tool to reach full speed before FIG.21
touching tool to work surface.

2. Apply minimum pressure to work
surface, allowing tool to operate at
high speed. Cutting rate is greatest

when the tool operates at high speed.

3. Once a cut is begun and a notch is
established in the workpiece, do not
change the angle of the cut. Changing

the angle will cause the wheel to bend
and may cause wheel breakage.

4. Remove the tool from work surface
before turning tool off. Allow the tool to

stop rotating before setting it down.

MAINTENANCE

A 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. An

accidental start-up can cause injury,

Cleaning

WARNING: Blow dirt and dust out of all air 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.

A 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.

17

Accessories

_ WARNING: Since accessories, other than those offered by
DEWALT, have not been tested with this product, use of such

accessories with this tool could be hazardous. To reduce the risk of
injury, only DEWALTrecommended 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-DEWALT (1-800-433-9258) or visit our website: www.

DEiWALT.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.

• CONFIRMATION OF OWNERSHIP: In case of an insurance

loss, such as fire, flood or theft, your registration of ownership will

serve as your proof of purchase.

• 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

DEiWALTwill 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-DF-:WALT (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.

Inaddition to the warranty, DEiWALTtools are covered by our:

1 YEAR FREE SERVICE

DEiWALTwill 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

DEWALTPower 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.

18

FREE WARNING LABEL REPLACEMENT: If your warning labels
become illegible or are missing, call 1-800-4-DEWALT (1-800-433-

9258) for a free replacement.

_WE×X×...................................................._;,,:i;;_.,;_.....................................................................................................

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MAXIMUg SPEEDMARKEDONTHE TOOL.ALWAYSUSEPROPERGUARDS

....................................................1

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19

D_finitions : lignes directrices en

mati_re de s_curit_

Les definitions ci-dessous decrivent le niveau de danger pour

chaque mot-indicateur employe. Lire le mode d'emploi et porter

une attention particuliere a.ces symboles.

i_ DANGER : indique une situation dangereuse imminente qui,

si elle n'est pas evitee, entraTnera la mort ou des blessures
graves.

_AVERTISSEMENT : indique une situation potentie//ement
dangereuse qui, si e//e n'est pas evitee, pourrait entra_ner /a
mort ou des blessures graves.

i_ATTENTION : indique une situation potentie//ement
dangereuse qui, si el/e n'est pas evitee, pourrait entra_ner des
blessures I_g_res ou modifies.

AVIS : indique une pratique ne posant aucun risque de

dommages corporels mais qui par contre, si rien n'est fair
pour /'eviter, pourrait poser des risques de dommages

materiels.

J

POUR TOUTE QUESTION OU REMARQUE AU SUJET DE CET
OUTIL OU DE TOUT AUTRE OUTIL DEWALT, COMPOSE LE

NUMFt:ROSANS FRAIS : 1-800-4-DEWALT (1-800-433-9258}.

_ VERTISSEMENT afin de reduire le risque de blessures, life

le mode d'emploi de I'outil.

Avertissements de s_curit_ g_n_raux
pour les outils _lectriques

s_curit_ et toutes les directives. Le non-respect des

_k AVERTISSEMENT ! Life tousles avertissements de

avertissements et des directives pourrait se solder par un
choc dectrique, un incendie et/ou une blessure grave.

CONSERVER TOUSLES AVERTISSEMENTS

ET TOUTES LES DIRECTIVES POUR UN

USAGE ULTERIEUR

Le terme _ outil dectrique _ cite dans les avertissements se rapporte

votre outil electrique a alimentation sur secteur (avec ill) ou par piles

(sansfi/).

1) S#CURIT# DU LIEU DE TRAVAIL

a) Ten#" I'aire de travail propre et bien _clair_e. /es Iieux

encombres ou sombres sont propices aux accidents.

b) Ne pas faire fonctionner d'outils _lectriques clans un

milieu d_flagrant, tel qu'en presence de liquides, de
gaz ou de poussi_res inflammables. Les outi/s e/ectriques

produisent des etincelles qui pourraient enflammer la poussiere

ou les vapeurs.

c) E-Ioigner les enfants et les personnes a proximit_ pendant

I'utilisation d'un outil _lectrique. Une distraction pourrait en
faire perdre la ma_trisea I'utilisateur.

2) SI_CURITI_ EN MATI#RE D'I_LECTRICITI_

a) Les fiches des outils _lectriques doivent correspondre

la prise. Ne jamais modifier la fiche d'aucune faqon.

Ne jamais utiliser de fiche d'adaptation avec un outil

_lectrique mis a la terre. Le risque de choc dectrique sera
reduit par I'utilisation de fiches non modifiees correspondant
la prise.

2O