DeWalt XR LI-ION DCG412 User manual

DCG412
20V Max* Cordless Grinder
Cordless Grinder sans fil 20 V max*
20 V Máx* Cordless Grinder
INSTRUCTION MANUAL
GUIDE D’UTILISATION
MANUAL DE INSTRUCCIONES
INSTRUCTIVO DE OPERACIÓN, CENTROS DE SERVICIO Y PÓLIZA DE
GARANTÍA. ADVERTENCIA: LÉASE ESTE INSTRUCTIVO ANTES DE
USAR EL PRODUCTO.
If you have questions or comments, contact us.
Pour toute question ou tout commentaire, nous contacter.
Si tiene dudas o comentarios, contáctenos.
1-800-4-DEWALT • www.dewalt.com

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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.
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.
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 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
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.
f) If operating a powertool in a damplocation is unavoidable,
use a ground fault circuit interrupter (GFCI) protected
supply. Use of a GFCI reduces the risk of electric shock.

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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.
f) 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) BATTERY TOOL USE AND CARE
a) Recharge only with the charger specified by the
manufacturer. A charger that is suitable for one type of
battery pack may create a risk of fire when used with another
battery pack.
b) Use power tools only with specifically designated battery
packs. Use of any other battery packs may create a risk of
injury and fire.

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c) When battery pack is not in use, keep it away from other
metal objects like paper clips, coins, keys, nails, screws,
or other small metal objects that can make a connection
from one terminal to another. Shorting the battery terminals
together may cause burns or a fire.
d) Under abusive conditions, liquid may be ejected from
the battery; avoid contact. If contact accidentally occurs,
flush with water. If liquid contacts eyes, additionally seek
medical help. Liquid ejected from the battery may cause
irritation or burns.
6) 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) Threaded mounting of accessories must match the
grinder spindle thread. For accessories mounted by flanges,
the arbor hole of the accessory must fit the locating diameter
of the flange. Accessories that do not match the mounting
hardware of the power tool will run out of balance, vibrate
excessively and may cause loss of control.
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.

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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 the power tool by insulated gripping surfaces
only, when performing an operation where the cutting
accessory may contact hidden wiring. 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.
l) 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.
p) Do not use Type 11 (flaring cup) wheels on this tool. Using
inappropriate accessories can result in injury.
q) Always use side handle. Tighten the handle securely. The
side handle should always be used to maintain control of the
tool at all times.
r) When starting the tool with a new or replacement wheel,
or a new or replacement wire brush installed, hold the
tool in a well protected area and let it run for one minute.
If the wheel has an undetected crack or flaw, it should burst in
less than one minute. If the wire brush has loose wires, they will
be detected. Never start the tool with a person in line with the
wheel. This includes the operator.
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 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 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.

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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 grinding surface of center depressed wheels must
be mounted below the plane of the guard lip. An
improperly mounted wheel that projects through the plane of
the guard lip cannot be adequately protected.
c) 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 and
accidental contact with wheel.
d) 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.
e) 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.
f) 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.

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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.
f) 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 and centrifugal forces.
c) Safety goggles or safety glasses with side shields and a
full face shield compliant with ANSI Z87.1 MUST be worn
by the operator and others that are within 50' (15.2 m) of
the use of this product.
Additional Safety Information
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 S12.6 (S3.19) hearing protection,
• NIOSH/OSHA/MSHA respiratory protection.
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.

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Your risk from these exposures varies, depending on how often you
do this 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 use NIOSH/OSHA approved respiratory protection appropriate
for the dust exposure. Direct particles away from face and body.
WARNING: Always wear proper personal hearing protection
that conforms to ANSI S12.6 (S3.19) during use. Under some
conditions and duration of use, noise from this product may
contribute to hearing loss.
WARNING: Always use eye protection. All users and
bystanders must wear eye protection that conforms to ANSI Z87.1.
WARNING: When not in use, place grinder on a stable
surface where it will not move inadvertantly, roll or cause a
tripping or falling hazard. The grinder may stand upright on the
battery pack but may be easily knocked over. Serious personal injury
may result.
CAUTION: To reduce the risk of personal injury, use extra care
when working into a corner or edge because a sudden, sharp
movement of the tool may be experienced when the wheel or other
accessory contacts a secondary surface or a surface edge.
• The label on your tool may include the following symbols. The
symbols and their definitions are as follows:
V................... volts A......................amperes
Hz................. hertz W.....................watts
min ............... minutes or AC..........alternating
or DC... direct current current
................. Class I Construction or AC/DC...alternating
.....................
(grounded) ........................or direct
................. Class II Construction current
(double insulated) no ....................no load
…/min .......... per minute speed
BPM ............. beats per minute
n ......................rated
IPM............... impacts per minute ........................speed
RPM ............. revolutions per .....................earthing
minute terminal
sfpm ............. surface feet .....................safety alert
..................... per minute symbol
SPM ...............strokes per minute
Important Safety Instructions for All
Battery Packs
When ordering replacement battery packs, be sure to include the
catalog number and voltage. Consult the chart at the end of this
manual for compatibility of chargers and battery packs.
The battery pack is not fully charged out of the carton. Before using
the battery pack and charger, read the safety instructions below and
then follow charging procedures outlined.
READ ALL INSTRUCTIONS
• Do not charge or use the battery pack in explosive
atmospheres, such as in the presence of flammable liquids,

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gases or dust. Inserting or removing the battery pack from the
charger may ignite the dust or fumes.
• NEVER force the battery pack into the charger. DO NOT
modify the battery pack in any way to fit into a non-
compatible charger as battery pack may rupture causing
serious personal injury. Consult the chart at the end of this
manual for compatibility of batteries and chargers.
• Charge the battery packs only in designated DEWALT chargers.
• DO NOT splash or immerse in water or other liquids.
• Do not store or use the tool and battery pack in locations
where the temperature may reach or exceed 105 ˚F (40˚C)
(such as outside sheds or metal buildings in summer). For
best life store battery packs in a cool, dry location.
NOTE: Do not store the battery packs in a tool with the
trigger switch locked on. Never tape the trigger switch in
the ON position.
WARNING: Fire hazard. Never attempt to open the battery pack
for any reason. If the battery pack case is cracked or damaged, do
not insert into the charger. Do not crush, drop or damage the battery
pack. Do not use a battery pack or charger that has received a sharp
blow, been dropped, run over or damaged in any way (e.g., pierced
with a nail, hit with a hammer, stepped on). Damaged battery packs
should be returned to the service center for recycling.
WARNING: Fire hazard. Do not store or carry the battery
pack so that metal objects can contact exposed battery
terminals. For example, do not place the battery pack in aprons,
pockets, tool boxes, product kit boxes, drawers, etc., with loose
nails, screws, keys, etc. Transporting batteries can possibly
cause fires if the battery terminals inadvertently come in
contact with conductive materials such as keys, coins, hand
tools and the like. The US Department of Transportation Hazardous
Material Regulations (HMR) actually prohibit transporting batteries in
commerce or on airplanes (e.g., packed in suitcases and carry-on
luggage) UNLESS they are properly protected from short circuits. So
when transporting individual battery packs, make sure that the battery
terminals are protected and well insulated from materials that could
contact them and cause a short circuit.
SPECIFIC SAFETY INSTRUCTIONS FOR LITHIUM ION (Li-Ion)
• Do not incinerate the battery pack even if it is severely
damaged or is completely worn out. The battery pack can
explode in a fire. Toxic fumes and materials are created when
lithium ion battery packs are burned.
• If battery contents come into contact with the skin,
immediately wash area with mild soap and water. If battery
liquid gets into the eye, rinse water over the open eye for 15
minutes or until irritation ceases. If medical attention is needed,
the battery electrolyte is composed of a mixture of liquid organic
carbonates and lithium salts.
• Contents of opened battery cells may cause respiratory
irritation. Provide fresh air. If symptoms persist, seek medical
attention.
WARNING: Burn hazard. Battery liquid may be flammable if
exposed to spark or flame.
The RBRC™ Seal
The RBRC™ (Rechargeable Battery Recycling
Corporation) Seal on the nickel cadmium, nickel metal
hydride or lithium ion batteries (or battery packs)
indicate that the costs to recycle these batteries (or
battery packs) at the end of their useful life have already
been paid by DEWALT. In some areas, it is illegal to place spent nickel
cadmium, nickel metal hydride or lithium ion batteries in the trash or
municipal solid waste stream and the RBRC program provides an
environmentally conscious alternative.