Bosch GWS18V-8B15 Assembly instructions

1-877-BOSCH99 (1-877-267-2499) www.boschtools.com
Operating/Safety Instructions
Consignes d’utilisation/de sécurité
Instrucciones de funcionamiento y seguridad
IMPORTANT
Read Before Using IMPORTANT Lire avant usage IMPORTANTE Leer antes de usar
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GWS18V-8

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Copyright © 2015, Infineon Technologies AG
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
conditions are met:
– Redistributions of source code must retain the above copyright notice, this list of conditions and the following
disclaimer.
– Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided with the distribution.
– Neither the name of the copyright holders nor the names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Licenses

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Safety Symbols
The definitions below describe the level of severity for each signal word.
Please read the manual and pay attention to these symbols.
This is the safety alert symbol. It is used to alert you to potential personal injury
hazards. Obey all safety messages that follow this symbol to avoid possible
injury or death.
DANGER indicates a hazardous situation which, if not avoided, will result in
death or serious injury.
WARNING indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
CAUTION indicates a hazardous situation which, if not avoided, could result in
minor or moderate injury.
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 power tool in a damp location
is unavoidable, use a Ground Fault Circuit
Interrupter (GFCI) protected supply. Use of an
GFCI 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 a dust mask, non-skid safety shoes, hard
hat, or hearing protection used for appropriate
conditions will reduce personal injuries.
Read all safety warnings, instructions, illustrations and specifications provided with
this power tool. Failure to follow all instructions listed below may result in electric shock,
fire and/or serious injury.
SAVE ALL WARNINGS AND INSTRUCTIONS FOR FUTURE REFERENCE
The term “power tool” in the warnings refers to your mains-operated (corded) power tool or battery-operated
(cordless) power tool.
General Power Tool Safety Warnings

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General Power Tool Safety Warnings
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 and clothing 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.
h. Do not let familiarity gained from frequent
use of tools allow you to become complacent
and ignore tool safety principles. A careless
action can cause severe injury within a fraction
of a second.
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 remove the battery pack, if
detachable, from the power tool before
making any adjustments, changing
accessories, or storing power tools. Such
preventive safety measures reduce the risk of
starting the power tool accidentally.
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 and accessories. Check
for misalignment or binding of moving parts,
breakage of parts and any other condition
that may affect the power tool’s operation. If
damaged, have the power tool repaired before
use. Many accidents are caused by poorly
maintained power tools.
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.
h. Keep handles and grasping surfaces dry,
clean and free from oil and grease. Slippery
handles and grasping surfaces do not allow
for safe handling and control of the tool in
unexpected situations.
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.
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.
e. Do not use a battery pack or tool that is
damaged or modified. Damaged or modified
batteries may exhibit unpredictable behavior
resulting in fire, explosion or risk of injury.

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Power Tool-Specific Safety Warnings
Safety Warnings Common for
Grinding, Sanding, Wire Brushing,
and Abrasive Cutting-Off
Operations:
This power tool is intended to function as a
grinder, sander, wire brush 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.
Operations such as polishing are not recommended
to be performed with this power tool. Operations for
which the power tool was not designed may create a
hazard and cause personal injury.
Do not use accessories 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.
The rated speed of the accessory must be at least
equal to the maximum speed marked on the power
tool. Accessories running faster than their rated speed
can break and fly apart.
The outside diameter and the thickness of your
accessory must be within the capacity rating of your
power tool. Incorrectly sized accessories cannot be
adequately guarded or controlled.
Threaded mounting of accessories must match the
grinder spindle thread. for accessories mounted
by flanges, the arbour 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.
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.
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.
Keep bystanders a safe distance away from work
area. Anyone entering the work area must wear
f. Do not expose a battery pack or tool to
fire or excessive temperature. Exposure to
fire or temperature above 265 °F may cause
explosion.
g. Follow all charging instructions and do not
charge the battery pack or tool outside
the temperature range specified in the
instructions. Charging improperly or at
temperatures outside the specified range may
damage the battery and increase the risk of fire.
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.
b. Never service damaged battery packs.
Service of battery packs should only be
performed by the manufacturer or authorized
service providers.
General Power Tool Safety Warnings

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personal protective equipment. Fragments of
workpiece or of a broken accessory may fly away and
cause injury beyond immediate area of operation.
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 could give the
operator an electric shock.
Never lay the power tool down until the accessory
has come to a complete stop. The spinning accessory
may grab the surface and pull the power tool out of your
control.
Do not run the power tool while carrying it at your
side. Accidental contact with the spinning accessory
could snag your clothing, pulling the accessory into your
body.
Regularly clean the power tool’s air vents. The
motor’s fan will draw the dust inside the housing and
excessive accumulation of powdered metal may cause
electrical hazards.
Do not operate the power tool near flammable
materials. Sparks could ignite these materials.
Do not use accessories that require liquid coolants.
Using water or other liquid coolants may result in
electrocution or shock.
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 kickout. 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.
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
reactions or kickback forces, if proper precautions are
taken.
Never place your hand near the rotating accessory.
Accessory may kickback over your hand.
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.
Use special care when working corners, sharp
edges etc. Avoid bouncing and snagging the
accessory. Corners, sharp edges or bouncing have a
tendency to snag the rotating accessory and cause loss
of control or kickback.
Do not attach a saw chain woodcarving blade or
toothed saw blade. Such blades create frequent
kickback and loss of control.
Safety Warnings Specific for
Grinding and Abrasive
Cutting-Off Operations:
Use only wheel types that are recommended for
your power tool and the specific guard designed for
the selected wheel. Wheels for which the power tool
was not designed cannot be adequately guarded and
are unsafe.
The grinding surface of centre 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.
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.
Wheels must be used only for recommended
applications. For example: do not grind with the
side of cut-off wheel. Abrasive cut-off wheels are
intended for peripheral grinding, side forces applied to
these wheels may cause them to shatter.
Always use undamaged wheel flanges that are of
correct size and shape for your selected wheel.
Proper wheel flanges support the wheel thus reducing
the possibility of wheel breakage. Flanges for cut-off
wheels may be different from grinding wheel flanges.
Do not use worn down wheels from larger power
tools. Wheel intended for larger power tool is not
suitable for the higher speed of a smaller tool and may
burst.
Power Tool-Specific Safety Warnings

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Additional Safety Warnings
Specific for Abrasive Cutting-Off
Operations:
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.
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.
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.
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.
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.
Do not use type 1 abrasive wheels designed for
straight grinding.
Do not attempt to cut large stock or sheets of metal
as this machine is not designed to be a dedicated
cut-off machine.
Safety Warnings Specific for
Sanding Operations:
Do not use excessively oversized sanding disc
paper. Follow manufacturer’s recom-mendations,
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 Wire
Brushing Operations:
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.
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 forces.
Power Tool-Specific Safety Warnings

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Additional Safety Warnings
Do not use AC only rated tools with a DC power
supply. While the tool may appear to work, the
electrical components of the AC rated tool are likely to
fail and create a hazard to the operator.
Keep handles dry, clean and free from oil and
grease. Slippery hands cannot safely control the power
tool.
Use clamps or other practical way to secure and
support the workpiece to a stable platform. Holding
the work by hand or against your body is unstable and
may lead to loss of control.
Develop a periodic maintenance schedule for
your tool. When cleaning a tool be careful not to
disassemble any portion of the tool since internal
wires may be misplaced or pinched or safety guard
return springs may be improperly mounted. Certain
cleaning agents such as gasoline, carbon tetrachloride,
ammonia, etc. may damage plastic parts.
Do not use vacuum or other dust collection system
when cutting metal. Sparks from metal cutting can
cause fire in the collector.
Some dust created by power
sanding, sawing, grinding,
drilling, and other construction activities contains
chemicals known 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 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.

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Symbols
IMPORTANT: Some of the following symbols may be used on your tool. Please study them and learn their meaning.
Proper interpretation of these symbols will allow you to operate the tool better and safer.
Symbol Designation ⁄ Explanation
V Volts (voltage)
A Amperes (current)
Hz Hertz (frequency, cycles per second)
W Watt (power)
kg Kilograms (weight)
min Minutes (time)
s Seconds (time)
Diameter (size of drill bits, grinding wheels, etc.)
nNo load speed (rotational speed at no load)
n Rated speed (maximum attainable speed)
...⁄min Revolutions or reciprocation per minute (revolutions, strokes, surface speed, orbits etc. per
minute)
 Off position (zero speed, zero torque...)
, , , ...
I, II, III, Selector settings (speed, torque or position settings. Higher number means greater speed)
Infinitely variable selector with off (speed is increasing from  setting)
Arrow (action in the direction of arrow)
Alternating current (type or a characteristic of current)
Direct current (type or a characteristic of current)
Alternating or direct current (type or a characteristic of current)
Class II construction (designates double insulated construction tools)
Earthing terminal (grounding terminal)
Warning symbol (alerts user to warning messages)
A
0
A
0
A
0
A
0
A
0
A
0
A
0


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Symbols (continued)
IMPORTANT: Some of the following symbols may be used on your tool. Please study them and learn their meaning.
Proper interpretation of these symbols will allow you to operate the tool better and safer.
Symbol Designation / Explanation
Alerts user to read manual
Alerts user to wear eye protection
Alerts user to wear respiratory protection
Alerts user to wear hearing protection
Alerts user to wear eye, respiratory, and hearing protection
This symbol designates that this tool is listed by Underwriters Laboratories.
This symbol designates that this tool is listed by Underwriters Laboratories, to United States
and Canadian Standards.
This symbol designates that this tool is listed by the Canadian Standards Association.
This symbol designates that this tool is listed by the Canadian Standards Association, to
United States and Canadian Standards.
This symbol designates that this tool is listed by the Intertek Testing Services, to United
States and Canadian Standards.
Designates Li-ion battery recycling program

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Functional Description and Specifications
Disconnect battery pack from tool before making any assembly, adjustments or
changing accessories. Such preventive safety measures reduce the risk of starting the tool
accidentally.
GWS18V-8
Cordless Angle Grinder with Side Switch
Grinding
Wheel Wheel
Guard
Hand Guard
(sold separately)
Side handle
Spindle
Lock
FIG. 1
Side
Switch
Battery
Pack
Release
Button
Battery Pack
Guard
Release
Lever
Battery Packs / Chargers:
Please refer to the battery/charger list, included with your tool.
NOTE: For tool specifications refer to the nameplate on your tool.
Accessory speed rating must be equal to or greater than the tool’s speed rating.
Do not exceed the recommended wheel diameter.
NOTE: Not recommended for use with type 11 cup wheels.
Lock Nut

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Model number GWS18V-8
Battery 18V (Bosch or AMPShare)
Rated speed n 11,000/min
Switch Type Side
Spindle thread 5/8"-11 UNC
Max. spindle length 9/16" (14,3 mm)
Max.Type 27 grinding wheel  4 1/2" (115mm)
Type 27 grinding wheel thickness 1/8" - 1/4" (3mm - 6mm)
Max.Type 41/1A, 27A/42 cutting wheel  4 1/2" (115mm)
Max. flap disc  4 1/2" (115mm)
Max. sanding disc  4 1/2" (115mm)
Max. wire wheel  4" (102mm)
Max. wire cup brush  3" (76 mm)
Functional Description and Specifications
Disconnect battery pack from tool before making any assembly, adjustments or
changing accessories. Such preventive safety measures reduce the risk of starting the tool
accidentally.
Inserting and Releasing
Battery Pack
This tool is equipped with Automatic Restart Protection.
This feature helps prevent accidental startups after
power has been interrupted, e.g. the battery was
removed with the switch locked in the on position.
To resume operation, turn the side switch to the off
position, and back to on position to restart the tool.
Make sure that the side switch (Fig. 1) is in the off
position before inserting or removing battery pack. To
insert the battery pack slide it into the housing until the
battery pack locks into position.
Your tool is equipped with a secondary locking latch to
prevent the battery pack from completely falling out of
the handle, should it become loose due to vibration.
To remove the battery pack, press the battery pack
release button and slide the battery pack forward.
Press the battery pack release button again and slide the
battery pack completely out of tool housing (Fig. 2).
Fig. 2
Assembly
Disconnect battery pack from tool before making any assembly, adjustments or
changing accessories. Such preventive safety measures reduce the risk of starting the tool
accidentally.

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Wheel Guard Installation
Wheel guard must be attached
when using disc grinding or
cutting wheels. Always keep wheel guard between you
and your work while grinding or cutting.
To attach wheel guard: Disconnect battery pack from
tool.
Press and hold the release lever (Fig. 3), and place the
guard on the guard mounting flange until the guard’s keys
line up with the notches in the spindle collar (Fig. 3A).
Press the guard onto the guard mounting flange until the
shoulder of the guard is seated against the flange of the
tool, and turn the guard until it can clearly be heard to
engage.
Adjust the position of the guard to the requirements
of the work process. For this, press the release lever
upward and turn the guard until it clicks into place then
adjust as needed.
• Always adjust the guard in such a manner that the two
cams of release lever engage into the corresponding
notches of the guard (Fig. 3B).
• Adjust the guard in such a manner that sparking is
prevented in the direction of the operator.
• The guard should turn only upon actuation of the
release lever! Otherwise the tool may not continue to
be used under any circumstances and must be taken
to an after-sales service agent.
Note: The encoding keys on the guard ensure that only a
guard that fits the tool type can be mounted.
To remove guard: Press release lever, rotate guard until
the keys on guard line up with the notches on the guard
mounting flange, and lift guard off the guard mounting
flange (Fig. 3).
Side Handle
The side handle is used to control and balance the tool.
The handle must be threaded into the front housing on
either side of the tool, depending on personal preference
and comfort. Use the side handle for safe control and
ease of operation (Fig. 1).
Hand Guard
(sold separately)
The hand guard is to be used with backing pads,
sanding discs and wire brushes to keep fingers and
hand away from work surface, sharp edges, burrs and
debris. When using the hand guard accessory (sold
separately), insert side handle through hole in guard
and then thread into housing (Fig. 1).
Ensure that hand guard is positioned between hand
and backing pad, sanding disc or wire brush.
Fig. 3
Guard
Mounting
Flange
Keys
Guard
Release
Lever
A B
Assembly

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Assembly
Lock Nut and Backing Flange
Your tool is equipped with a threaded spindle for
mounting accessories. Always use the supplied original
BOSCH lock nut, and backing flange, that has the same
thread size as the spindle. Backing flange is keyed to
output shaft (Fig. 4). Always make sure that the lock nut
is tightened correctly with the supplied wrench.
Disc Grinding Wheel Assembly
1. Disconnect battery pack from tool.
2. Be sure that wheel guard is in place for grinding.
3. Place BACKING FLANGE and GRINDING WHEEL on
the spindle.
4. Thread on the lock nut and tighten nut using the lock
nut wrench, while holding the spindle lock. (Fig. 4).
TO REMOVE: Reverse procedure.
WHEN USING SPIN-ON WHEELS
1. Disconnect battery pack from tool.
2. Be sure that wheel guard is in place for grinding.
3. Thread wheel directly onto spindle without using the
supplied flanges.
TO REMOVE: Reverse procedure.
All parts of a spin-on wheel must be within lip of grinding
guard (Fig. 5). If spin-on wheel is past lip of guard, do
not use that wheel as it does not fit on this grinder.
Do not use accessories that
run eccentrically. The tool will
vibrate excessively and may cause loss of control and the
accessory may burst. Lock Nut
Type 27
Grinding
Wheel Backing
Flange
Spindle
Type 27
Grinding
Wheel
Spindle
Type 27
Wheel
Guard
Backing
Flange
Fig. 4
Lock Nut
FIG. 5
Spin-On
Wheel
Lip of
Guard

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Abrasive Type 41/1A and 27A/42
Wheel Assembly
Using the Type 41/1A wheel guard (sold separately), it
is possible to perform limited cutting on small stock such
as metal tubes, piping or rebar.
Do not attempt to cut large stock or sheets of metal as
this tool is not designed to be a dedicated cutting tool.
Always use Type 41/1A
protection guard for cutting.
1. Disconnect battery pack from tool.
2. Be sure that wheel guard is in place for cutting.
When using mounting wheels, place the BACKING
FLANGE on the spindle and then place the WHEEL on
the spindle.
3. Thread on the lock nut and tighten nut using the lock
nut wrench, while holding the spindle lock. (Fig. 6).
TO REMOVE: Reverse procedure.
Type 1 Abrasive Straight Grinding
Wheels
Do not use Type 1 abrasive
wheels designed for straight/
die grinding. This tool is not designed for use with Type
1 abrasive straight/die grinding wheels.
Type 41/1A
Wheel Guard
(sold separately)
Spindle
Backing
Flange
Type 41/1A
Cutting Wheel
Fig. 6
Type 27A/42
Cutoff Wheel
Lock Nut
Assembly

-16-
Sanding Accessories Assembly
BACKING PAD
Before attaching a backing pad
be sure its maximum safe
operating speed is not exceeded by the nameplate
speed of the tool.
Wheel guard may not be used
for most sanding operations.
Always reinstall wheel guard when converting back to
grinding operations.
Do not use the quick -
Clamping Nut with backing pad
for sanding accessories.
TO INSTALL BACKING PAD AND
SANDING DISC (sold separately)
Disconnect battery pack from tool.
Attach hand guard (Fig. 1). Set the tool on its top side
(spindle up). Place the rubber backing pad onto the
spindle shaft. Center the sanding disc on top of the
backing pad. Insert the lock nut (sold separately)
through the disc and thread onto the spindle as far as
you can with your fingers. Press in the spindle lock, then
tighten the backing pad securely with lock nut wrench
(Fig. 7).
TO REMOVE: Reverse procedure.
Wire Brush Assembly
Before assembling wire brush to this tool, disconnect
from the power source. Attach hand guard (Fig. 1). Wire
brushes are equipped with their own threaded hub,
simply thread on to spindle. Be sure to seat against
shoulder before turning tool “ON”.
TO REMOVE: Reverse procedure.
Wire Wheel Assembly
Before assembling wire wheel to this tool, disconnect
from the power source. Attach type 27 guard (Fig. 8).
Wire wheels are equipped with their own threaded hub,
simply thread on to spindle. Be sure to seat against
shoulder before turning tool “ON”.
TO REMOVE: Reverse procedure.
Sanding
Disc
Backing
Pad
Lock Nut
(sold separately)
Wire Brush
Spindle
Fig. 7
Assembly
SPINDLE
TYPE 27
WHEEL GUARD
WIRE WHEEL
FIG. 8

-17-
Concrete Dust Extraction
Attachment for Surfacing Grinding
Assembly
A type 27 grinding wheel guard
may not be used for all tool
operations. Do not discard guard when not in use.
Always reinstall wheel guard when converting back to
grinding operations.
Dust Extraction Attachment is
not a guard, do not use with
bonded abrasive wheels. Dust extraction attachment
may not protect operator in the event of a wheel burst.
TO INSTALL CONCRETE DUST
EXTRACTION ATTACHMENT (FIG. 9)
1. Unplug tool from power source.
2. Position appropriate attachment on spindle neck with
dust port pointing away from tool body.
3. Rotate attachment clockwise 90º until guard clicks in
place.
4. Adjust attachment by depressing guard release button
and rotate to desired position.
5. Allow guard release button to click in place.
6. Place the backing flange on the spindle.
7. Place the diamond cup wheel onto the spindle and
align with the flange.
8. Thread the lock nut onto the spindle with the lock nut
relief facing the accessory.
9. Tighten lock nut with supplied lock nut wrench while
holding spindle lock.
When using spin on wheels, follow steps 1 - 5, then
thread wheel directly onto spindle without using the
supplied flanges.
TO REMOVE: Reverse procedure.
Spindle
CONCRETE DUST EXTRACTION
ATTACHMENT
Wheel
guard Spindle neck
FIG. 9
Assembly

-18-
Masonry Cutting Guard
Assembly
A type 27 grinding wheel guard
may not be used for all tool
operations. Do not discard guard when not in use.
Always reinstall wheel guard when converting back to
grinding operations.
To improve ergonomics of your grinder when cutting
masonry, gearbox must be rotated relative to the
position of the switch as the tool was assembled at the
factory.
ROTATE GEARBOX (Fig. 10)
1. Unplug tool from power source.
2. Completely unscrew the four screws between the gear
housing and motor body.
3. Rotate gear housing to the proper orientation without
removing motor from the housing.
For the slide switch models, rotate gear housing 180
degrees in the direction indicated in Fig 11, so the
switch is 90 degrees from the spindle.
4. Screw in and tighten the four screws you removed.
5. The screw holding the quick release lever is longer
than the other screws, this long screw must stay
with the quick release lever when re-attaching gear
housing for the quick release button to operate
properly.
6. Attach proper dust collection guard with foot and
accessory.
INSTALLING MASONRY TYPE 1
CUTTING GUARD
1. Use tool adjusted as show in figures 10 and 11.
2. Unplug tool from power source.
3. Unscrew and remove side handle.
4. Slide dust extraction guard on spindle neck.
5. Rotate attachment until stability bracket and hole for
side handled are aligned.
0 mm
4x
4x
FIG. 10
Slide
switch
180
degrees
180
degrees
FIG. 11
Spring
Guard
release
lever
(x3)
Assembly

-19-
Assembly
6. Screw in side handle to secure stability bracket
between the tool housing and handle.
7. Adjust guard to desired depth of cut.
TO REMOVE: Reverse procedure.
INSTALLING DRY DIAMOND WHEEL
(Fig. 12)
1. Place the backing flange on the spindle. Turn flange
until it locks with the base of the spindle.
2. Place the dry diamond wheel onto the spindle and
align the arbor hole of the grinding wheel with the
shoulder of the backing flange.
3. Tighten lock nut with supplied lock nut wrench while
holding spindle lock.
TO REMOVE: Reverse procedure.
FIG. 12
Spindle
Lock nut
Backing
flange
Dry
diamond
wheel
Lock nut
Backing
flange
Spindle
Dry diamond
wheel

-20-
Operating Instructions
Hold the tool with both hands
while starting the tool, since
torque from the motor can cause the tool to twist.
Start the tool before applying to work and let the tool
come to full speed before contacting the workpiece. Lift
the tool from the work before releasing the switch. DO
NOT turn the switch “ON” and “OFF” while the tool is
under load; this will greatly decrease the switch life.
Side On-Off Switch
with Lock
The tool is switched “ON” by the side switch located at
the side of the motor housing (Fig. 13). The switch can
be locked in the “ON” position, a convenience for long
grinding operations.
To turn the tool “ON” without locking it, move the switch
forward by applying pressure ONLY at the REAR portion
of the switch. When pressure is released the switch will
return to “OFF” position.
TO LOCK THE SWITCH “ON”, move the switch forward
and press the FRONT portion.
TO UNLOCK THE SWITCH, simply press and release the
REAR portion of the slider. Switch is spring loaded and
will snap back automatically.
Side
Switch
Fig. 13