BOSCH GWG12V-20S Cordless Right Angle Die Grinder Instruction Manual

June 1, 2024
Bosch

Instruction Manual
GWG12V-20S
Operating / Safety Instructions

IMPORTANT
Read Before Using
Call Toll Free for Consumer Information & Service Locations
1-877-BOSCH99 (1-877-267-2499) www.boschtools.com

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 per- sonal 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.

General Power Tool Safety Warnings

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.

  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, radia- tors, 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 a GFCI reduces the risk of electric shock.

  3. Personal safety
    a. Stay alert, watch what you are doing and use common sense when operating 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.
    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 connec-tion 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 bet-ter 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 ac- cessories, 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. Prop-erly 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 instruc-tions, taking into account the working conditions and the work to be performed.
    Use of the power tool for operations differ-ent from those intended could result in a hazardous situation.
    h. Keep handles and grasping surfaces dry, clean and free from oil and grease. Slip-pery 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 unpredict-able behaviour resulting in fire, EXPLOSION or risk of injury.
    f. Do not expose a battery pack or tool to fire or excessive temperature. Exposure to fire or temperature above 265 °F/130 °C may cause explosion.
    g. Follow all charging instructions and do not charge the battery pack or tool out-side 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 identi-cal replacement parts. This will ensure that the safety of the power tool is main-tained.
    b. Never service damaged battery packs.
    Service of battery packs should only be per-formed by the manufacturer or authorized service providers.

Power Tool-Specific Safety Warnings

  1. Safety warnings common for grinding, sanding, wire brushing, polishing or carving operations:
    a. This power tool is intended to function as a grinder, sander, wire brush, polisher, or carving tool. Read all safety warnings, in-structions, 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. Operations such as 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.
    c. Do not use accessories which are not specifically designed and specified by the tool manufacturer. Just because the acces-sory can be attached to your power tool, it does not assure safe operation.
    d. The rated speed of the accessories 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.
    e. The outside diameter and the thickness of your accessory must be within the capac-ity rating of your power tool. Incorrectly sized accessories cannot be adequately guarded or controlled.
    f. The arbour size of wheels, sanding drums or any other accessory must properly fit the spindle or collet of the power tool.
    Accessories that do not match the mount-ing hardware of the power tool will run out of balance, vibrate excessively and may cause loss of control.
    g. Mandrel mounted wheels, sanding drums, cutters or other accessories must be fully inserted into the collet or chuck. If the mandrel is insufficiently held and/or the overhang of the wheel is too long, the mounted wheel may become loose and be ejected at high velocity.
    h. 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 inspect-ing 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.
    i. Wear personal protective equipment.
    Depending on application, use face shield, safety goggles or safety glasses. As ap- propriate, wear dust mask, hearing protec-tors, 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 applications. The dust mask or respirator must be capable of filtrating par- ticles generated by the particular applica-tion. Prolonged exposure to high intensity noise may cause hearing loss.
    j. 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.
    k. Hold the power tool by insulated grip-ping surfaces only, when performing an operation where the cutting accessory may contact hidden wiring. Contact with a “live” wire will also make exposed metal parts of the power tool “live” and could give the operator an electric shock.
    l. Always hold the tool firmly in your hand(s) during the start-up. The reaction torque of the motor, as it accelerates to full speed, can cause the tool to twist.
    m. Use clamps to support workpiece whenev-er practical. Never hold a small workpiece in one hand and the tool in the other hand while in use. Clamping a small workpiece allows you to use your hand(s) to control the tool. Round material such as dowel rods, pipes or tubing have a tendency to roll while being cut, and may cause the bit to bind or jump toward you.
    n. 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.
    o. After changing the bits or making any adjustments, make sure the collet nut, chuck or any other adjustment devices are securely tightened. Loose adjustment devices can unexpectedly shift, causing loss of control, loose rotating components will be violently thrown.
    p. Do not run the power tool while carrying it at your side. Accidental contact with the spinning accessory could snag your cloth-ing, pulling the accessory into your body.
    q. 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.
    r. Do not operate the power tool near flam-mable materials. Sparks could ignite these materials.
    s. Do not use accessories that require liquid coolants. Using water or other liquid cool-ants may result in electrocution or shock.

  2. 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.
    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 move-ment 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 con-ditions 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. The operator can control kickback forces, if proper precau-tions are taken.
    b. Use special care when working corners, sharp edges etc. Avoid bouncing and snag-ging the accessory. Corners, sharp edges or bouncing have a tendency to snag the rotating accessory and cause loss of control or kickback.
    c. Do not attach a toothed saw blade. Such blades create frequent kickback and loss of control.
    d. Always feed the bit into the material in the same direction as the cutting edge is exiting from the material (which is the same direction as the chips are thrown).
    Feeding the tool in the wrong direction causes the cutting edge of the bit to climb out of the work and pull the tool in the direction of this feed.
    e. When using rotary files, high-speed cut-ters or tungsten carbide cutters, always have the work securely clamped. These wheels will grab if they become slightly canted in the groove, and can kickback.
    When a rotary file, high-speed cutter or tungsten carbide cutter grabs, it may jump from the groove and you could lose control of the tool. NOTE: Only those accessories are listed that are permitted to be used with the tool. Do not attach a saw chain woodcarving blade, segmented diamond wheel with a peripheral gap greater than 10 mm (13/32”) or toothed saw blade. Such blades create frequent kickback and loss of control.

  3. Safety warnings specific for
    grinding and abrasive cutting-off operations
    a. Use only wheel types that are recom-mended for your power tool and only for recommended applications. For example: do not grind with the side of a cut-off wheel. Abrasive cut-off wheels are intended for peripheral grinding, side forces applied to these wheels may cause them to shatter.
    b. For threaded abrasive cones and plugs use only undamaged wheel mandrels with an unrelieved shoulder flange that are of correct size and length. Proper mandrels will reduce the possibility of breakage.
    c. Do not “jam” a cut-off wheel or apply excessive pressure. Do not attempt to make an excessive depth of cut. Over-stressing the wheel increases the loading and susceptibility to twisting or snagging of the wheel in the cut and the possibility of kickback or wheel breakage.
    d. Do not position your hand in line with and behind the rotating wheel. When the wheel, at the point of operation, is moving away from your hand, the possible kickback may propel the spinning wheel and the power tool directly at you.
    e. When wheel is pinched, snagged 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 correc-tive action to eliminate the cause of wheel pinching or snagging.
    f. Do not restart the cutting operation in the workpiece. Let the wheel reach full speed and carefully re-enter the cut. The wheel may bind, walk up or kickback if the power tool is restarted in the workpiece.
    g. Support panels or any oversized work-piece to minimize the risk of wheel pinch-ing 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.
    h. 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.

  4. 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 apply-ing excessive load to the brush. The wire bristles can easily penetrate light clothing and/or skin.
    b. Allow brushes to run at operating speed for at least one minute before using them. During this time no one is to stand in front or in line with the brush. Loose bristles or wires will be discharged during the run-in time.
    c. Direct the discharge of the spinning wire brush away from you. Small particles and tiny wire fragments may be discharged at high velocity during the use of these brushes and may become imbedded in your skin.

Additional Safety Warnings

Do not use AC only rated tools with a DC pow-er 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 op-erator.
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 plat-form. Holding the work by hand or against your body is unstable and may lead to loss of con-trol.
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 improp-erly 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 pow-er sanding, sawing, grind-ing, 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, de-pending on how often you do this type of work. To reduce your exposure to these chemi-cals: 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.

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
Alerts user to read manual.
V Volts (voltage)
W Watt (power)

| Direct current (type or a characteristic of current)
⌀| Diameter (size of drill bits, grinding wheels, etc.)
“| Inches (dimension)
mm| Millimeters (dimension)
n| Rated speed (maximum attainable speed)
RPM| Revolutions per minute (speed)
+| Increases speed (RPM)
–| Decreases speed (RPM)
| Arrow (action in the direction of arrow)
| Alerts user to wear eye protection.
| Alerts user to wear respiratory protection.
| Alerts user to wear hearing protection.
| This symbol designates that this tool is listed by the Canadian Standards Association, to United States and Canadian Standards.
| Designates Li-ion battery recycling program.

Getting to Know Your Cordless Right Angle Die Grinder

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. 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.

1 Collet
2 Collet Nut
3 Spindle
4 Spindle Lock Bar
5 Spindle Direction Indicator
6 LED Indicator Lights (battery charge level and speed)| 7 Speed Selection Buttons
8 Battery Pack
9 Battery Release Tabs
10 Switch Lock-off
11 Paddle Switch
12 Handle (insulated grip)
13 LED Indicator Lights Label
---|---

Specifications

Model number GWG12V-20S
Battery 12V Max (Bosch series)
Max no load speed 16,000 RPM
Switch type Paddle
Max collet ⌀ 5/16” (8 mm)
Max grinding wheel ⌀ 2″ (50 mm)
Spanner flat on clamping nut 17 mm
Permitted ambient temperature during charging +32…+95°F (0…+35°C)
Permitted ambient temperature during operation +5…+122°F (-15…+50°C)
Permitted ambient temperature during storage -4…+122°F (-20…+50°C)

Functional Description

Automatic Restart Protection
Helps prevent accidental startups after power has been interrupted, e.g. the battery was re-moved or discharged, or the tool stops due to overload while the switch was in the on posi-tion. To resume operation, turn on/off switch to the off position, then restart the tool.
Constant Response Circuity
Helps maintain near constant RPMs between no-load and load conditions.
Overload Protection
Helps protect tool from excessive heat that may damage the motor. If all the LED indicator lights flash yellow and the tool stops or slows during operation, allow motor to cool for 30 seconds by running no-load. If the overload protection stops the tool repeatedly, excessive force is causing the tool to overload. Stop excessive force and readjust work piece to reduce force applied.

Intended Use

Use this right angle die grinder only as intended. Unintended use may result in personal injury and property damage.
This tool is intended for light: grinding, sanding, wire brushing, polishing, and carving, applica-tions on metal, wood, plastic, stone, ceramic, leather and other materials. To perform any applica-tion, mandrel mountable accessories, or accessories having shank diameter measuring 1/4″ must be used. All accessories used with this tool may not have a working diameter larger than two (2) inches. Each accessory used with this tool must be carefully selected for the application, and may include engraving cutters, tungsten carbide cutters, aluminum carbide grinding stones, polishing points, small wire brushes and other similar accessories.

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.

Changing the Collet
(Fig. 2)
This tool includes a pre-installed 1/4″ collet, within the collet nut, and is to be used with a 1/4″ diameter accessory shank. This assembly may be replaced with a larger 5/16″ (max size) collet and nut assembly for 5/16″ diameter ac- cessory shanks. Consult Bosch Service Center for selection and availability of 5/16″ collet.
To replace the collet assembly:

  1. Pull the Spindle Lock Bar 4 out to lock the Spindle 3.
  2. Loosen the Collet Nut 2 with the included 17 mm Wrench 14.
  3. Unscrew and remove the collet and collet nut assembly.
  4. Ensure that the spindle threads are clean and the collet is properly fitted in the Col- let Nut 2.
  5. By hand, screw the new collet assembly onto the Spindle 3.

Accessory Assembly
(Fig. 3, Fig. 4)
Only use accessories with Maximum Safe Operating Speed rated at least equal to the maximum speed marked on the power tool. Accessory running faster than their rated speed can break and fly apart, and cause injury or property dam- age.
Do not pull the spindle locking bar while the spin-dle is moving. The power tool may become damaged if you do this.
Do not use accessories that run eccentrically. The tool will vibrate excessively and may cause loss of control and the accessory may burst.
Before attaching selected accessory, ensure that the spindle, collet, collet nut, and acces-sory shank are clean. The accessory shank must be straight, undamaged, and an appropriate size in relation to the collet. Grinding wheels must be held by a backing pad and not exceed 2″ in diameter.

  1. Pull the Spindle Lock Bar 4 out to lock the Spindle 3 (Fig. 3).

  2. Loosen the Collet Nut 2 with the included 17 mm Wrench 14 (Fig. 3).

  3. Insert the shank of the Backing Pad Acces-sory 15 all the way into the Collet 1 (Fig. 4).
    Note: For all other accessory types, ensure that the shank is inserted a minimum of 1″.

  4. Firmly clamp the accessory shank by tightening the Collet Nut 2 with the 17 mm Wrench 14 (Fig. 4).

  5. Push the Spindle Lock Bar 4 in to release the Spindle 3 (Fig. 4).

Assembly

Inserting and Removing Battery Pack

If battery release tabs are cracked or otherwise dam-aged, do not insert into tool. Battery can fall out during operation.
Inserting the Battery Pack
To insert the Battery Pack 8, align it and slide it into the tool until it locks into position.
Removing the Battery Pack
(Fig. 5)
Release the Battery Pack 8 from the tool by pressing on the two Battery Release Tabs 9, found on either side of the Battery Pack 8, then pull and remove the Battery Pack 8. Do not force.

Operation

Hold the tool with both hands while starting the tool, since torque from the motor can cause the tool to twist.
On-Off Switch
(Fig. 6)
To switch the tool on, push the Switch Lock-off 10 forward. Then squeeze the Paddle Switch 11. To turn the tool off, release the Paddle Switch 11.
Start the tool before applying to a workpiece, and let the tool come to the desired speed before contacting the workpiece. Lift the tool from the workpiece before releasing the Paddle Switch 11. DO NOT turn the switch “ON” and “OFF” while the tool is under load. This will greatly decrease the switch life. Speed Selection
(Fig. 7)
Press the Speed Selection Buttons 7 to select the desired speed. The selected speed will be displayed on the LED Indicator Lights 6 as a white light. See the table below for the speed for each setting.

LED Indicator Max Speed (RPM)
1 x continuous white light 5,000
2 x continuous white light 7,500
3 x continuous white light 10,000
4 x continuous white light 12,500
5 x continuous white light 15,000

LED Indicator Lights
Battery Charge LED Indicator Lights
(Fig. 7)
The 5 LEDs of the LED Indicator Light 6 indicate the state of the battery charge, as listed in the table below. After start-up, the LED Indicator Light 6 will light up for 5 seconds.

LED Indicator Capacity
5 x continuous green light 80-100%
4 x continuous green light 60-80%
3 x continuous green light 40-60%
2 x continuous green light 20-40%
1 x continuous yellow light 1-20%
1 x continuous red light 0-1%

LED Indicator Lights Label
(Fig. 7, Fig. 8)
The information on the LED Indicator Lights label 13 is for reference only. The actual speed or bat-tery charge may vary slightly.
The LED Indicator Lights Label 13, applied be-low the Spindle Direction Indicator 5, shows the LED Indicator Light 6 color for the battery capacity and speed setting. The first row refer-ences the maximum level of battery charge per number of indicator lights, matched with the re-spective LED color. Second row references the selected speed per number of indicator lights, matched with the respective LED color. Use the table below to determine the status of the tool by reading the LED indicator lights 6.

LED Color Indicator Status Meaning/Cause Solution
White Continuous light (1x to 5x) Indicates the speed that has been
selected. See “Speed Selection” on page 14.
Green Continuous light (2x to 5x) Indicates the battery charge status. See

“Battery Charge LED Indicator Lights” on page 14.
Yellow| Continuous light (1x)| The battery is almost empty.| Replace or charge the bat- tery soon.
Flashing Light| Critical temperature has been reached (motor, electronics, battery).| Run the power at no load and allow it to cool down.
Red| Continuous light (1x)| The battery is empty. (See “Battery Charge LED Indicator Lights” on page 14).| Replace or charge the battery.
Flashing Light (5x)| The power tool is overheated and will switch off.| Allow the power tool to cool down. Then switch the tool on.
The power tool is jammed and will switch off.| Remove the blockage. Then switch the tool on.
The spindle lock is ac- tivated and the power tool will shut off.| Push in the spindle lock bar. Then switch the tool on.

Maintenance

To avoid accidents, always disconnect the tool and/or charger from the pow-er supply before servicing or cleaning.
Service
NO USER SERVICEABLE PARTS INSIDE. Preventive maintenance performed by un­au­thorized per-sonnel may result in misplacing of internal wires and components which could cause se-rious hazard. We recom­mend that all tool ser- vice be performed by a Bosch Factory Service Center or Authorized Bosch Service Station.
SERVICEMEN: Disconnect tool and/or charger from power source before servicing.
Batteries
Be alert for battery packs that are nearing their end of life. If you notice decreased tool performance or significantly shorter running time between charges then it is time to replace the battery pack. Failure to do so can cause the tool to operate improperly or damage the charger.
Tool Lubrication
Your Bosch tool has been properly lubricated and is ready for use.
D.C. Motors
The motor in your tool has been engineered for many hours of dependable service. To maintain peak efficiency of the motor, we recommend it be examined every six months. Only a genuine Bosch replacement motor specially designed for your tool should be used.
Cleaning
Certain cleaning agents and solvents damage plastic parts. Some of these are: gasoline, carbon tet-rachloride, chlorinated cleaning solvents, am-monia and household detergents that contain ammonia.
Ventilation openings and switch levers must be kept clean and free of foreign matter. Do not attempt to clean by inserting pointed objects through opening.
Accessory Storage and Maintenance
Store accessories in a cool dry place and avoid freezing. Before use, check accessory for cracks and fractures, do not use if damage is suspected.

Accessories and Attachments

Do not use attachments/accessories other than those specified by Bosch. Use of attachments/accessories not specified for use with the tool described in this manual may result in damage to tool, property damage, and or personal injury.
Only use accessories (sold separately):

  • Rated for a speed of 16,000 RPM
  • Maximum diameter of 2 inches (50 mm)
  • Held by a backing pad that are a maximum diameter of 2 inches (50 mm) when ap-plicable
  • Straight shank with a diameter of 1/4″ (6 mm) or 5/16″ (8 mm)

Licenses
Copyright © 2016 STMicroelectronics
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 STMicroelectronics nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permis- sion.

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 (INCLUD-ING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Copyright © 2009–2020 ARM LIMITED
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 ARM 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;
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Copyright © 2018-2019 STMicroelectronics. All rights reserved.
Version 2.0, January 2004
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Copyright © 2017 STMicroelectronics
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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 HOLDER 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.

LIMITED WARRANTY
For details on the terms of the limited warranty for this product, go to https://rb-pt.io/PowerToolWarranty or call 1-877-BOSCH99.

© Robert Bosch Tool Corporation
1800 W. Central Road
Mt. Prospect, IL 60056-2230
160992A8P5 04/2023
GWG12V-20S Die Grinder OSI Final for Approval 20230627.indd 6/27/2023 10:52:44 AM

References

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