Bosch GWS8-45 User Manual

IMPORTANT: IMPORTANT : IMPORTANTE:

Read Before Using Lire avant usage Leer antes de usar

Operating/Safety Instructions
Consignes de fonctionnement/sécurité
Instrucciones de funcionamiento y seguridad

For English Version Version française Versión en español
See page 2 Voir page 16 Ver la página 30

1-877-BOSCH99 (1-877-267-2499) www.boschtools.com

Call Toll Free for

Consumer Information

& Service Locations

Pour obtenir des informations

et les adresses de nos centres

de service après-vente,

appelez ce numéro gratuit

Llame gratis para

obtener información

para el consumidor y

ubicaciones de servicio

GWS8-45

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 1

-2-

Read all safety warnings
an d al l in s truct i ons.

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 all of the warnings
refers to your mains-operated (corded) power
tool or battery-operated (cordless) power tool.

Work area safety

Keep work area clean and well lit. Cluttered

or dark areas invite accidents.

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.

Keep children and bystanders away while
operating a power tool. Distractions can

cause you to lose control.

Electrical safety

Power tool plugs must match the outlet.
Never modify the plug in any way. Do not
us e a ny a dapte r pl ugs with ea r thed
(grounded) power tools. Unmodified plugs

and matching outlets will reduce risk of electric
shock.

Av oid body con tact wit h ea rthe d or
grounded surfaces such as pipes, radiators,
ra nges and refr iger ator s. Ther e is an

increased risk of electric shock if your body is
earthed or grounded.

Do not expose power tools to rain or wet
conditions. Water entering a power tool will

increase the risk of electric shock.

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.

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 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.

Personal safety

Stay alert, watch what you are doing and
us e comm on s ense when opera ting 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.

General Power Tool Safety Warnings

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, will
result in death or serious injury.

CAUTION, used with the safety alert symbol, indicates a hazardous
situation which, if not avoided, will result in minor or moderate injury.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 2

-3-

Use personal protective equipment. Always
w

ear eye protection. Protective equipment

such as dust mask, non-skid safety shoes,
ha rd hat, or h eari ng p rote ctio n used for
appropriate conditions will reduce personal
injuries.

Prevent unintentional starting. Ensure the
sw itch i s i n the of f-po siti on befo re
connecting to power source and / or battery
pack, pick ing up o r c arry ing the tool .

Carrying power tools with your finger on the
switch or energizing power tools that have the
switch on invites accidents.

Re move any adju stin g key o r wrenc h
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.

Do not overreach. Keep proper footing and
balance at all times. This enables better

co ntro l of the powe r tool in une xpec ted
situations.

Dress properly. Do not wear loose clothing
or jewelry. Keep your hair, clothing and
gloves away from moving parts. Loose

clothes, jewelry or long hair can be caught in
moving parts.

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.

Power tool use and care

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.

Do not use the power tool if the switch does
not turn it on and off. Any power tool that

ca nnot be cont rolle d with the swi tch is
d

angerous and must be repaired.

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.

Store idle power tools out of the reach of
ch ildr en and do no t al low pers ons
unfamiliar with the power tool or these
instructions to operate the power tool.

Power tools are dangerous in the hands of
untrained users.

Ma inta in po wer tools . Ch eck 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.

Use the power tool, accessories and tool
bi ts etc . in acc orda nce wi t h thes e
in stru ctio ns, ta king in to acc ount the
working conditions and the work to be
pe rfor med. Us e o f t he powe r t ool for

operations different from those intended could
result in a hazardous situation.

Service

Ha ve your power tool serv iced by a
qualified repair person using only identical
replacement parts. This will ensure that the

safety of the power tool is maintained.

Power Tool-Specific Safety Warnings

Safety Warnings Common for Grinding,

Sanding and Wire Brushing Operations:

This power tool is intended to function as a
grinder, sander or wire brush tool. Read all
safety warnings, instructions, illustrations
an d s pecif icat ions provid ed 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 or cutting off
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 eq ual t o t h e m a ximum speed
marked on the power tool. Accessories

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 3

-4-

running faster than their RATED SPEED can
b

reak 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
arbor hole of the accessory must fit the
lo c ating d iamete r of the FL A NGE.

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
abra sive wheels f or 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
fo r damag e or ins tall an und amag ed
accessory. After inspecting and installing
an a c cess ory, po siti on y ours elf 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.

We ar per sona l prote ctiv e equip ment .
Depending on application, use face shield,
sa fety goggl es or safety glass es. As
ap prop riat e, w ear dust ma sk, hearin g
protectors, gloves and workshop apron
capable of stop pin g 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
pa rtic les gene rate d b y yo ur opera tion .
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 personal protective equipment.

Fr agme nts of wor kpie ce or of a broke n
accessory may fly away and cause injury
beyond immediate area of operation.

Hold the power tool by insulated gripping
su rfac es on ly, when perf ormi ng an
operation where the cutting accessory may
contact hidden wiring or its own cord.

Cutting accessory contacting a “live” wire may
make exposed metal parts of the power tool

“live” and could give the operator an electric
s

hock.

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.

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 th e

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
ho usin g and exce ssiv e acc umul atio n of
powdered metal may cause electrical hazards.

Do n ot o pera te the pow er tool nea r
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,
de pend ing on d irect ion of t he w heel’ 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 operat ing 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

re acti ons or ki ckba ck forc es, if pr oper
precautions are taken.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 4

-5-

Never place your hand near the rotating
a

ccessory. Accessory may kickback over your

hand.

Do not position your body in the area where
power tool will move if kickback occurs.

Kickb ack will prop el the tool in dir ecti on
opposite to the wheel’s movement at the point
of snagging.

Use special care when working corners,
sh arp edges etc. Avoi d b ounc ing 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

Operations:

Us e on ly wheel typ es 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 the operator from broken wheel
fragments, accidental contact with wheel and
sparks that could ignite clothing.

Wh eels mu st be used on ly for
recommended applications. For example:

do not grind with the side of cut-off wheel.

A

brasi ve cut-off wheels are inte nde d f or
peripheral grinding, side forces applied to these
wheels may cause them to shatter.

Always use undamaged wheel flanges that
are of corre ct 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.

Safety Warnings Specific for

Sanding Operations:

Do not use excessively oversized sanding
di sc pape r. Foll ow manuf actu rer’ s
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 Wire

Brushing Operations:

Be aware that wire bristles are thrown by
the brush even during ordinary operation.
Do not overstress the wires by applying
ex cess ive load to t he b rush . The wi re

bristles can easily penetrate light clothing
and/or skin.

If the use of a guard is recommended for
wi r e b rushi n g, d o n ot a llow 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.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 5

Additional Safety Warnings

-6-

GFCI and personal protection devices like
electrician’s rubber gloves and footwear will
further enhance your personal safety.

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 suppor t the workpi ece 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 you r tool. W hen cle aning a tool be
careful not to disassemble any portion of
th e tool sin c e inter nal wire s may be
misplaced or pinched or safety guard return
sp ring s may be improp erly mount ed.

Certain cleaning agents such as gasoline,
carbon tetrachloride, ammonia, etc . may
damage plastic parts.

Risk of injury to user. The power cord must only
be serviced by a Bosch Factory Service Center
or Autho rized Bosch Service Station.

Us e h and gua rd when sa ndin g a nd
brushing.

Do no t u se T ype 1 a bras ive whee ls
designed for straight grinding.

Do not use cutting wheels (e.g. Type 41/1A
or Type 4 2/2 7A) w ith thi s grinder. The

provided guard is intended for Type 27 grinding
wheels only and may not contain or deflect
swarf, particles or fragments during cutting
process.

Do not use Type 6 or Type 11 cup wheels
with this grinder. The provided guard is

intended for Type 27 grinding wheels and will
not contain or deflect swarf, particles, or wheel
fragments during grinding with cup wheels.

Some dust crea ted by

power sanding, sawing,
grinding, drilling, and other construction
activities contains chemicals known to
ca use ca ncer , birth defect s 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.

Yo u r ri s k fro m the s e ex p o sures v a r i es,
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.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 6

Symbols

-7-

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

0

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)

0 Off position (zero speed, zero torque...)

1, 2, 3, ...

I, II, III,

Selector settings (speed, torque or position settings. Higher number means
greater speed)

0

Infinitely variable selector with off (speed is increasing from 0 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)

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 7

-8-

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

Designates Li-ion battery recycling program

Designates Ni-Cad battery recycling program

Alerts user to read manual

Alerts user to wear eye protection

This symbol designates that this tool is listed by Underwriters Laboratories.

This symbol designates that this component is recognized 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.

This symbol designates that this tool complies to NOM Mexican Standards.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 8

-9-

Functional Description and Specifications

Disconnect the plug from the power source b efore making any
assembly, adjustments or changing accessories. Such preventive

safety measures reduce the risk of starting the tool accidentally.

Angle Grinder

VENTILATION

OPENINGS

GRINDING

WHEEL

WHEEL
GUARD

HAND GUARD

(Optional Accessory)

SIDE HANDLE

SPINDLE LOCK

FIG. 1

SWITCH
BUTTON

WRENCH AND

STORAGE AREA

VIBRATION CONTROL

SIDE HANDLE

(Optional Accessory)

Model Number GWS8-45

Amps 7.5
Volts AC 120
Rated Speed (RPM), /min 11000
Spindle Thread 5/8"-11
Max. grinding wheel ⌀ 4-1/2" (115mm)
Grinding wheel thickness

1/4" (6 mm)
Max. sanding disc ⌀ 4-1/2" (115mm)
Max. flap disc ⌀ 4-1/2" (115mm)
Max. wire wheel ⌀ 4" (102mm)
Max. wire cup wheel ⌀ 3" (76mm)

NOTE 1: 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 2: Not recommended for use with type 11 cup wheels.

Application Capability

Metal Grinding (Type 27) X
Metal Grinding (Type 11) N
Metal Grinding (Type 1) N
Metal Cutting (Type 41/1A) N
Concrete Surfacing O
Concrete/Masonry Cutting N
Sanding O
Wire Brushing (Wheel) X
Wire Brushing (Cup) O

X = Tool is capable to perform this

application.

O = Tool is capable to perform this

application with optional
attachments

N = Tool is not capable of this

application.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 9

WHEEL GUARD INSTALLATION

Wh e el guard must be

attached when using disc
grinding or cutting wheels. Always keep wheel
guard be tween you an d y our work while
grinding or cutting.

To attach wheel guard DISCONNECT tool
from power source.

Position guard on spindle neck so that the
notches on guard line up with the keys on the
spindle neck (Fig. 2).

The position of the guard can be adjusted to
accommodate the operation being performed.

Rotate guard in either direction to desired
position, and tighten screw with the hex wrench
provided to secure guard in place.

TO REMOVE GUARD: Loosen screw with the
hex wrench provided, rotate guard until the

notches on guard line up with the keys on the
spindle neck, and lift guard off the spindle neck
(Fig. 2).

FIG. 2

Assembly

-10-

LOCK NUT AND BACKING FLANGE

Your tool is equipped with a threaded spindle
for mounting ac ces sories. Always use the
supplied lock nut (and backing flange) that
has same thread size as spindle.

VIBRATION CONTROL SIDE HANDLE

(Optional Accessory)

The side handle is used to control and balance
the tool. The handle must be thread ed into the
fr o nt h ousing on either side o f the t ool,
de p endin g on per so nal pref e rence an d
comfort. Use the side handle for safe control
and ease of operation (Fig. 1).

OPTIONAL HAND GUARD

(Optional Accessory)

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
optional hand guard accessory 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.

KEYS

NOTCHES

SCREW

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 10

-11-

GRINDING WHEEL ASSEMBLY

D

isconnect tool from power source. Be sure
that wheel guard is in place for grinding. Place
BACKING FLANGE and GRINDING WHEEL
on the spindle. Thread on the lock nut and
tighten nut using the supplied lock nut wrench,
while holding the spindle lock in (Fig. 3).

TO REMOVE: Reverse procedure.
No t re c o m m ended f o r us e wi t h sp i n-on

wheels.

LOCK NUT

TYPE 27

GRINDING

WHEEL

BACKING

FLANGE

SPINDLE

TYPE 27

GRINDING

WHEEL

LOCK NUT

SPINDLE

TYPE 27

WHEEL GUARD

BACKING

FLANGE

FIG. 3

SANDING ACCESSORIES ASSEMBLY

BACKING PAD

Before attaching a

backing pad be sure its
maximum sa f e operating sp e e d is not
exceeded by the nameplate speed of the
tool.

Wheel guard may not be

used fo r most sanding
operation s. Alwa ys reinstall wheel guard
when converting back to grinding operations.

TO INSTALL BACKING PAD AND

SANDING DISC

Disconnect tool from power source.

Attach hand guard (Fig. 1). Set the tool on its
to p sid e (sp i n d l e up ) . Pl a c e th e ru b b e r
backing pad onto the spindle shaft. Center
the sanding disc on top of the backing pad.
Insert the l ock nu t thro ugh 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. 4).

TO REMOVE: Reverse procedure.

SANDING

DISC

BACKING

PAD

LOCK NUT

WIRE

BRUSH

SPINDLE

FIG. 4

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 11

Operating Instructions

Ho l d the t o o l with b oth

hands while starting the
tool, since torque from the motor can cause the
tool to twist.

Start the tool 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.

SLIDE ON-OFF SWITCH WITH LOCK

Th e tool is swit ched “ON” by the s witc h
bu t t o n lo c a t e d at the side o f th e mot o r
housing. The switch can be locked in the

“ON” positi o n , a co n ve n i e n c e for long
grinding operations.

TO TURN THE TOOL “ON” without locking it,
slide the switch button forward by applying
pressure ONLY at the REAR portion of the
button. When pressure is released the switch
button will snap to “OFF” position (Fig. 1).

TO LOCK THE SWITC H “ON”, slide th e
switch button forward and press “IN ” the
FRONT portion.

TO UNLOCK THE SWITCH, simply press
and release the REAR portion of the button.
Switch is spring loaded and will snap back
automatically.

SELECTING GRINDING WHEELS

Befo re using a gri ndi ng

wheel, be certain that its
ma ximu m s a fe opera ting spe ed i s n ot
exceeded by the nameplate speed of the
grinder. Do not exceed the recom mended
wheel diameter.

GRINDING WHEELS

Grinding wheels should be carefully selected in
orde r to use the grinder most effici ent ly.
Wh eels vary in typ e of abrasi ve, bond,
hardness, grit size and structure. The correct
type of wheel to use is determined by the job.
Us e g rind ing whee ls for fast grind ing of
structura l ste el, heavy weld beads, ste el
casting, stainless steel and other ferro us
metals.

GRINDING TIPS

Efficient grinding is achieved by controlling the
pressure and keep ing the angle between wheel
and workpiece at 10° to 15°. If the wheel is flat,
the tool is difficult to control. If the angle is too
steep, the pressure is concentrated on a small
area causing burning to the work surface.

Ex c essiv e or s u dden

pressure on the wheel will
sl ow g rind i ng actio n and pu t d a nger o us
stresses on the wheel.

When grinding with a new wheel be certain to
grind while pulling tool backwards until wheel
becomes rounded on its edge. New wheels
have sharp corners which tend to “bite” or cut
into work piece when pushing forward.

Grinding Operations

-12-

WIRE BRUSH ASSEMBLY

B

efore assembling wire brush to this tool,
disconnect from the power source. Attach
hand gu a r d (Fi g . 1). Wi r e bru s h e s 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

B

efore assembling wire wheel to this tool,
disconnect from the power source. Attach type
27 guard (Fig. 2). 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.

BM 2610043215_GWS8-45 1/29/16 1:58 PM Page 12

-13-

Sanding Operations

SELECTING SANDING DISC

Sanding discs are made of extremely hard
and sharp aluminum oxide grits, phenol-resin
bonded to a sturdy fiber backing for fast
heavy-duty service and long life. The discs
vary as to size and spacing of the abrasive
grits. OPEN COAT (type H) — used for soft
materials and on paint or varnish. CLOSED
COAT (type K) —used for metal, hardwood,
stone, marble and other materials.

Sanding discs range in grit from 16 (very
coarse) to 180 (very fine). To obtain best
results, select sanding discs carefully. Many
jobs require the use of several grit sizes and
at times both “open coat and closed coat”
discs are required to get the job done faster.
See chart for application examples.

Operation: Refinishing painted wood or metal surfaces.

REMARKS GRIT

To remove paint and to smooth Coarse

surface irregularities. 16-24-30

To smooth Medium
the rough sanding. 36-50-80

To remove scratches left by Fine
previous discs. 100-120

To smooth surfaces for painting, Very Fine
polishing or waxing. 150-180

SANDING TIPS

For best results, tilt the Disc Sander at a 10° to
15° angle while sanding so that only about 1"
of the surface around the edge of the disc
contacts the work.

If the disc (accessory) is

held flat or the back edge
of the disc comes in contact with the work, a
violent thrust to the side may result.

If sander is tilted too much, sanding action will
be too gr eat and a roug h cut su rfac e o r
gouging and snagging will result.

Guide the Disc Sander with crosswise strokes.
Be careful not to hold the sander in one spot
too long. Do not use a circular motion, as this
makes swirl marks. Test before use on scrap stock.

Do not force or apply pressure when sanding.
Use only the weight of the tool for pressure.
Excess pressure actually slows the tool down.
If faster stock removal is desired, change to a
coarser grit disc.

Remove gummy paint from metal with an
“open coat” disc. Sand until sparks start to
appear, then stop and change to a “closed
coat” disc to remove any remaining paint.

SANDING WOOD

When sanding wood the direction of the disc
motion at the contact point should parallel the
grain as much as possible. The rapid cut of
discs and the swirl type scratch pattern they
occasionally create generally prohibit their use
for producing the final finish.

Scratches and circular marks are usually the
re s ult of usi ng to o coa rse a grit . Whe n
changing to a finer grit, move across the sand ­ing lines that were made by a previous coarser
disc.

SANDING METAL

When sanding automobiles or appliances,
wipe the metal clean with a non-flammable
solvent or commercial cleaner to remove all
wa x and grease. By d o ing this fi rst, th e
sanding discs will sand better and last longer.

For heavy duty work, use a coarse grit disc
first. Follow-up with a medium grit to remove
scratches. To produce smooth finish, use fine
grit disc.

BM 2610043215_GWS8-45 1/29/16 1:59 PM Page 13

Wire brushes are intended to “clean” structural
st e el, casting s , she et met al, st one an d
concrete. They are used to remove rust, scale
and paint.

Av o i d bo uncing and

snagging the wire brush,
especially when working corners, sharp edges
etc. This can cause loss of control and kick­back.

BRUSHING PRESSURE

1. Remember, the tips of a wire brush do the
work. Ope rat e t he brush with the lightes t

pressure so only the tips of the wire come in
contact with the work.

2. If heavier pressures are used, the wires will
be overstressed, resulting in a wiping action;
and if this is continued, the life of the brush
will be shortened due to wire fatigue.

3. Apply the brush to the work in such a way
that as much of the brush face as possible is
in full contact with the work. Applying the side
or edge of the brush to the work will result in
wire breakage and shortened brush life.

Wire Brush Operations

CORRECT:

Wire tips doing

the work.

INCORRECT:

Excessive

pressure can

cause wire

breakage.

CORRECT:

Wire tips doing

the work.

INCORRECT:

Excessive pressure

can cause wire

breakage.

WIRE WHEEL BRUSH

WIRE CUP BRUSH

-14-

Service

Preventive maintenance

performed by unautho ­rized personnel may result in misplacing of
inter nal wires and co mponent s w hich
could cause serious hazard. We recommend

that all tool service be performed by a Bosch
Factory Service Center or Autho rized Bosch
Service Station.

TOOL LUBRICATION

Your Bosch tool has been properly lubricated
and is ready to use. It is recommended that
tools with gears be regreased with a special
gear lubricant at every brush change.

CARBON BRUSHES

The brushes and commutator in your tool have
be e n en ginee r ed for ma ny hours of
de p endab l e serv i ce. To m a intai n peak
efficiency of the motor, we recommend every
two to six months the brush es be examined.

Only genuine Bosch replace ment brushes
specially designed for your tool should be used.

BEARINGS

After about 300-400 hours of operation, or at
every second brush change, the bearings
should be replaced at Bosch Factory Service
Center or Au thorized Bosch Service Station.
Bearings which become noisy (due to heavy
load or very abrasive material cut ting) should
be replaced at once to avoid overheating or
motor failure.

Cleaning

To avoi d acc i dents

always dis conn ect the
tool from the power supply before cleaning
or performing any main tenance. The tool

ma y be cle a ned mo s t effe c tivel y with
compressed dry air. Always wear safety gog -

gles when cleaning tools with compressed
air.

Maintenance

BM 2610043215_GWS8-45 1/29/16 1:59 PM Page 14