Atlas Copco GTG25-F120-13 Instruction sheet

GTG25 F120-13
Printed Matter No. 9839 0065 01 Turbine Grinders
Publication Date 2020-02-24
Valid from Serial No. B2410001 Product Instructions
GTG25-F120-13
(12000 r/min)
(12000 rpm)
8423252501
WARNING
Read all safety warnings and instructions
Failure to follow the safety warnings and instructions may result in
electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference

EN GTG25 F120-13
2© Atlas Copco Industrial Technique AB - 9839 0065 01
A 17 Nm
B L = 900 mm (35") (RUBAIR16)
C 16 mm (5/8")
D 6.3 bar (-90 psig)
E 12000 r/min (rpm)
F 15 Nm

3
© Atlas Copco Industrial Technique AB - 9839 0065 01
Table of Contents
Product Information................................................................................................5
General Information ..........................................................................................5
Safety Signal Words ..............................................................................5
Warranty ................................................................................................5
ServAid ..................................................................................................5
Website..................................................................................................6
Safety Data Sheets MSDS/SDS............................................................6
Product safety video for grinders...........................................................6
Installation of Vibrating Tools ................................................................6
Country of Origin ...................................................................................6
Dimensional Drawings...........................................................................6
Overview...........................................................................................................7
Main parts..............................................................................................7
Technical Product Data .........................................................................7
Service Overview..............................................................................................7
Service Recommendations....................................................................7
Service interval overview.......................................................................8
Installation ...............................................................................................................9
Installation Requirements .................................................................................9
Air quality...............................................................................................9
Compressed Air Connection..................................................................9
Installation Instructions .....................................................................................9
Visual inspection - air installation ..........................................................9
Visual inspection - tools and accessories..............................................9
Installation overview ............................................................................10
Operation ...............................................................................................................11
Ergonomic Guidelines.....................................................................................11
Configuration Instructions ...............................................................................11
Wheel configuration options ................................................................11
Lever assembly options.......................................................................12
Operating Instructions.....................................................................................13
Verifying free speed.............................................................................13
Adjusting support handle .....................................................................14
Adjusting wheel guard .........................................................................15
Operating the grinder...........................................................................16
Service ...................................................................................................................18
Maintenance Instructions................................................................................18
Service Recommendations..................................................................18
Preventive Maintenance ......................................................................18
Service instructions .............................................................................18
Lubrication Instructions...................................................................................22
Lubricating guide .................................................................................22

4© Atlas Copco Industrial Technique AB - 9839 0065 01
Troubleshooting....................................................................................................23
Troubleshooting ..............................................................................................23
Recycling ...............................................................................................................24
Environmental Regulations.............................................................................24
Recycling information .....................................................................................24

GTG25 F120-13 EN Product Information
© Atlas Copco Industrial Technique AB - 9839 0065 01 5
Product Information
General Information
WARNING Risk of Property Damage or Severe Injury
Ensure that you read, understand and follow all instructions before operating the tool. Failure to follow
all the instructions may result in electric shock, fire, property damage and/or severe bodily injury.
►Read all Safety Information delivered together with the different parts of the system.
►Read all Product Instructions for installation, operation and maintenance of the different parts of
the system.
►Read all locally legislated safety regulations regarding the system and parts thereof.
►Save all Safety Information and instructions for future reference.
Safety Signal Words
The safety signal words Danger, Warning, Caution, and Notice have the following meanings:
DANGER DANGER indicates a hazardous situation which, if not avoided, will result in death or se-
rious injury.
WARNING WARNING indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
CAUTION CAUTION, used with the safety alert symbol, indicates a hazardous situation which, if
not avoided, could result in minor or moderate injury.
NOTICE NOTICE is used to address practices not related to personal injury.
Warranty
■Product warranty will expire 12 months after the product is first taken into use, but will in any case ex-
pire at the latest 13 months after delivery.
■Normal wear and tear on parts is not included within the warranty.
■Normal wear and tear is that which requires a part change or other adjustment/overhaul during
standard tools maintenance typical for that period (expressed in time, operation hours or other-
wise).
■The product warranty relies on the correct use, maintenance, and repair of the tool and its component
parts.
■Damage to parts that occurs as a result of inadequate maintenance or performed by parties other
than Atlas Copco or their Certified Service Partners during the warranty period is not covered by the
warranty.
■To avoid damage or destruction of tool parts, service the tool according to the recommended mainte-
nance schedules and follow the correct instructions.
■Warranty repairs are only performed in Atlas Copco workshops or by Certified Service Partners.
Atlas Copco offers extended warranty and state of the art preventive maintenance through its ToolCover
contracts. For further information contact your local Service representative.
For electrical motors:
■Warranty will only apply when the electric motor has not been opened.
ServAid
ServAid is a portal that is continuously updated and contains Technical Information, such as:
■Regulatory and Safety Information
■Technical Data

Product Information EN GTG25 F120-13
6© Atlas Copco Industrial Technique AB - 9839 0065 01
■Installation, Operation and Service Instructions
■Spare Parts Lists
■Accessories
■Dimensional Drawings
Please visit: https://servaid.atlascopco.com.
For further Technical Information, please contact your local Atlas Copco representative.
Website
Information concerning our Products, Accessories, Spare Parts and Published Matters can be found on
the Atlas Copco website.
Please visit: www.atlascopco.com.
Safety Data Sheets MSDS/SDS
The Safety Data Sheets describe the chemical products sold by Atlas Copco.
Please consult the Atlas Copco website for more information www.atlascopco.com/sds.
Product safety video for grinders
Learn more about safety features on Atlas Copco grinders and what measures the operator has to take for
a safe operation. Click the link or scan the QR code below to view the video:
https://www.youtube.com/watch?v=XK_dHwli8-Q
Installation of Vibrating Tools
We recommend using a minimum length of 300 mm (12") of flexible hose for compressed air between a vi-
brating tool and the quick-action coupling.
Country of Origin
For the Country of Origin, please refer to the information on the product label.
Dimensional Drawings
Dimensional Drawings can be found either in the Dimensional Drawings Archive, or on ServAid.
Please visit: http://webbox.atlascopco.com/webbox/dimdrw or https://servaid.atlascopco.com.

GTG25 F120-13 EN Product Information
© Atlas Copco Industrial Technique AB - 9839 0065 01 7
Overview
Main parts
Position Part Function
1 Support handle Adjustable for a flexible working position for left or right handed
operator.
2 Auto balancer Reduces vibrations.
3 Wheel guard Adjustable wheel guard allows flexible positioning. Prevents the
operator to come in contact with the grinding wheel and protect
the operator in the event of a bursting wheel.
4 Spindle locking button/Wheel
guard adjustment
Dual functionality. Locking spindle by pushing forward. Adjusting
wheel guard by pulling backward.
5 Data plate Shows general information about the tool.
6 Security mechanism A two-step function for a safe start and stop of the tool. Press the
release arm (6a) forward to release the safety looking arm (6b)
7 Throttle handle Offers an ergonomic, comfortable and safe grip as well as good
temperature insulation.
8 Exhaust air outlet Allows adjustable direction of exhaust air in 360 degrees for
healthy and comfortable operations.
9 Whip hose Facilitates air connection handling and protects the tool from im-
purities.
10 Throttle lever Starts and stops the tool.
11 Sign Shows the tools nominal speed.
Technical Product Data
Technical Product Data can be found on either ServAid, or the Atlas Copco website.
Please visit: https://servaid.atlascopco.com or www.atlascopco.com.
Service Overview
Service Recommendations
Preventive maintenance is recommended at regular intervals. See the detailed information on preventive
maintenance. If the product is not working properly, take it out of service and inspect it.

Product Information EN GTG25 F120-13
8© Atlas Copco Industrial Technique AB - 9839 0065 01
If no detailed information about preventive maintenance is included, follow these general guide-
lines:
■Clean appropriate parts accurately
■Replace any defective or worn parts
Service interval overview
The table below shows the recommended service intervals for this tool, including what parts to service af-
ter 350, 700 and 1000 working hours.
The 1 000 hours service must only be carried out by authorized workshop or qualified service technician.
350 hours service 700 hours service 1 000 hours service
Inspect tool visually Inspect tool visually Inspect tool visually
Change oil Change oil Change oil
Clean filters Clean filters Clean filters
Service turbine
Service spindle

GTG25 F120-13 EN Installation
© Atlas Copco Industrial Technique AB - 9839 0065 01 9
Installation
Installation Requirements
Air quality
Poor air quality may cause damage to the tool and reduce the performance.
■For optimum performance and maximum product life we recommend the use of compressed air with
a maximum dew point of +10°C (50°F). We also recommend to install an Atlas Copco refrigeration
type air dryer.
■Use a separate air filter which removes solid particles larger than 30 microns and more than 90% of
liquid water. Install the filter as close as possible to the product and prior to any other air preparation
units to avoid pressure drop.
■Lubrication free tools are a better choice from an environmental perspective.
■Lubrication will shorten the life time of the turbine motor and once lubricated, you will need to con-
tinue with the lubrication.
Compressed Air Connection
WARNING Risk of severe injury
Air under pressure can cause injury.
►Always shut off the air supply when not in use or before any adjustments.
►Drain the hose of air pressure and disconnect the tool from air supply when not in use or before
any adjustments.
►Always use the correct hose size and air pressure for the tool.
WARNING Compressed Air
High air pressure can cause severe damage and bodily injury.
►Do not exceed maximum air pressure.
►Make sure that there are no damaged or loose hoses or fittings.
For correct air pressure and hose size, see the Technical Product Data on - https://
servaid.atlascopco.com or www.atlascopco.com.
Make sure that the hose and couplings are clean and free from dust before connecting to the tool.
Installation Instructions
Visual inspection - air installation
Inspect the air installation visually from the supply point to the tool before use.
■Hose
■Couplings
■System pressure
■Air filter
Look for any damage that can compromise the safety of the tool.
Visual inspection - tools and accessories
Inspect the tool and its parts visually before use.
The parts in the list below may vary depending on model.
■Wheel guard or Backing pad

Installation EN GTG25 F120-13
10 © Atlas Copco Industrial Technique AB - 9839 0065 01
■Adapters, nuts or flange washers
■Support handle
■Throttle lever and security mechanism
■Autobalancer
■Spindle
Look for any damage, grease or oil leakage that can compromise the safety of the tool.
Installation overview
Legend to page 2
A) Recommended torque
B) Whip hose length
C) Hose diameter
D) Max working air pressure
E) Recommended torque
F) Max free speed

GTG25 F120-13 EN Operation
© Atlas Copco Industrial Technique AB - 9839 0065 01 11
Operation
Ergonomic Guidelines
Consider your workstation as you read through this list of general ergonomic guidelines to identify areas
for improvement in posture, component placement, or work environment.
■Take frequent breaks and change work positions frequently.
■Adapt the workstation area to your needs and the work task.
■Adjust for a convenient reach range by determining where parts and tools need to be located to
avoid static load.
■Use workstation equipment such as tables and chairs appropriate for the work task.
■Avoid work positions above shoulder level or with static holding during assembly operations.
■When working above shoulder level, reduce the load on the static muscles by lowering the weight
of the tool, using for example torque arms, hose reels or weight balancers. You can also reduce
the load on the static muscles by holding the tool close to the body.
■Take frequent breaks.
■Avoid extreme arm or wrist postures, particularly during operations requiring a degree of force.
■Adjust for a convenient field of vision that requires minimal eye and head movements.
■Use appropriate lighting for the work task.
■Select the appropriate tool for the work task.
■In noisy environments, use ear protection equipment.
■Use high-quality inserted tools and consumables to minimize exposure to excessive levels of vibra-
tion.
■Minimize exposure to reaction forces.
■When cutting:
A cut-off wheel can get stuck if the cut-off wheel is bent or not guided properly. Use the correct
flange for the cut-off wheel and avoid bending the cut-off wheel during operation.
■When drilling:
The drill might stall when the drill bit breaks through. Use support handles if the stall torque is high.
The safety standard ISO11148 part 3 recommends using a device to absorb a reaction torque
above 10 Nm for pistol grip tools and 4 Nm for straight tools.
■When using direct-driven screwdrivers or nutrunners:
Reaction forces depend on the tool settings and joint characteristics. Strength and posture deter-
mine the amount of reaction force that an operator can tolerate. Adapt the torque setting to the op-
erator's strength and posture and use a torque arm or reaction bar if the torque is too high.
■In dusty environments, use a dust extraction system or wear a mouth protection mask.
Configuration Instructions
Wheel configuration options
The table below shows the configuration options for different wheel types with applicable attachment
parts.
For Ordering No please see section Spare part list and Accessories. For installation instruction of wheel
please see section Operation.

Operation EN GTG25 F120-13
12 © Atlas Copco Industrial Technique AB - 9839 0065 01
Pos. Item A. Grinding B. Cutting-off
1 Wheel Type 27, Type 42 Type 41
Max diameter 125 mm, 5” 125 mm, 5”
Thickness 0.5 - 7.0 mm 0.5 - 7.0 mm
Hole diameter 22 mm 22 mm
Peripherical speed 80 m/s 80 m/s
2 Flange washer locking wheel Ø 41 mm Ø 58 mm
Service tool Allen key, 6 mm Allen key, 6 mm
Recommended torque 20 Nm 20 Nm
Lever assembly options
WARNING Risk of injury
►Always shut off air supply, drain hose of air pressure and disconnect tool from air supply when not
in use, before changing accessories or when making repairs.
►Always wear protective gloves when changing accessories or when making repairs.
1. Remove the lever by using a screwdriver.
2. Remove the two screws that holds the release holder.
3. Seal the screw holes with the two screws in the lever kit.
4. Push in the replacement lever by using a screwdriver.

GTG25 F120-13 EN Operation
© Atlas Copco Industrial Technique AB - 9839 0065 01 13
Operating Instructions
Verifying free speed
WARNING Risk of severe injury
Air under pressure can cause injury.
►Always shut off the air supply when not in use or before any adjustments.
►Drain the hose of air pressure and disconnect the tool from air supply when not in use or before
any adjustments.
►Always use the correct hose size and air pressure for the tool.
WARNING Risk of injury
►Always lock autobalancer with applicable part before starting the tool.
►Never measure free speed with a wheel attached.
►Measure the free speed daily.
Required tools
■Allen key
■Tachometer
Instructions
1. Press the spindle lock button forward and keep it pressed while tightening the flange washer using
an allen key.
2. Connect the tool to the air supply.
3. Put a tachometer in the spindle hole.
4. Start the tool and measure the speed at a pressure of 6.3 bar.
Make sure that the throttle lever is pressed down to the bottom and measure the speed for at
least 1 minute
5. Remove the tachometer.
6. Verify the free speed on the tachometer with the speed marked on the tool.
WARNING Risk of injury
■The measured speed must not exceed the stated maximum speed marked on the tool. Re-
turn the tool to an authorized service center in the event of overspeeding.

Operation EN GTG25 F120-13
14 © Atlas Copco Industrial Technique AB - 9839 0065 01
Adjusting support handle
WARNING Risk of severe injury
Air under pressure can cause injury.
►Always shut off the air supply when not in use or before any adjustments.
►Drain the hose of air pressure and disconnect the tool from air supply when not in use or before
any adjustments.
►Always use the correct hose size and air pressure for the tool.

GTG25 F120-13 EN Operation
© Atlas Copco Industrial Technique AB - 9839 0065 01 15
Required tools
■Allen key (stored within the handle)
Instructions
1. Loosen the support handle using an allen key.
2. Adjust the support handle in a suitable position.
3. Tighten the support handle with the screw to the recommended torque.
WARNING Risk of injury
■Make sure that the wheel guard is put in a suitable position before operating the tool.
Adjusting wheel guard
DANGER Risk of Injury
There is a risk of injury if the tool is used without the wheel guard.
►Always use the tool with the recommended wheel guard.
►Make sure that the wheel guard is positioned correctly and not damaged.
WARNING Risk of severe injury
Air under pressure can cause injury.
►Always shut off the air supply when not in use or before any adjustments.
►Drain the hose of air pressure and disconnect the tool from air supply when not in use or before
any adjustments.
►Always use the correct hose size and air pressure for the tool.
Instructions
1. Pull and hold the spindle lock button.
2. Turn the wheel guard in a suitable position. Position the wheel guard between yourself and the grind-
ing wheel.
WARNING Risk of injury
■Make sure that the wheel guard is put in a suitable position before operating the tool.
3. Release the spindle lock button.

Operation EN GTG25 F120-13
16 © Atlas Copco Industrial Technique AB - 9839 0065 01
Operating the grinder
DANGER Risk of Injury
There is a risk of injury if the tool is used without the wheel guard.
►Always use the tool with the recommended wheel guard.
►Make sure that the wheel guard is positioned correctly and not damaged.
WARNING Risk of injury
►Always use applicable protective equipment when working with the tool such as; eye protection,
hearing protection and non skid safety shoes.
►Always wear protective gloves when replacing accessories or when making repairs.
►Make sure that the working area is kept free from other people to prevent injuries.
►Make sure that the workpiece is safely attached.
►Make sure that the air hose is not under pressure before connecting the tool to the air supply.
►Never remove or attach the throttle lever or security mechanism with tape or similar.
►Make sure that the selected combination of abrasive equipment and attachments parts corre-
spond to national regulations.
►Make sure that the abrasive equipment is not cracked or damaged.
►Make sure that the maximum speed of the abrasive equipment is higher than or equal to the
speed marked on the tool.
►Make sure that the speed of the tool is not higher than the maximum rated speed marked on the
tool.
►When working with the tool, always hold the tool with two hands and in such a way that they are
kept away from moving parts.
►Always operate the tool in the recommended working direction.
►Never touch any rotating parts when the tool is running or connected to the air line.
►Never use the tool above head height.
►Stop using the tool if abnormally loud noises and vibrations occur during use.
Instructions
1. Connect the tool to the air supply (if not already connected).
2. Direct the air exhaust on the handle away from the operator.
3. Press the release arm forward to release the security mechanism.
4. Press down the throttle lever to start the grinder. Replace the throttle lever if it is not working prop-
erly.
WARNING Risk of Damage and Injury
Rotating parts may cause damage and injury
►Make sure that the tool is switched off and has stopped rotating before putting it down.

GTG25 F120-13 EN Operation
© Atlas Copco Industrial Technique AB - 9839 0065 01 17

Service EN GTG25 F120-13
18 © Atlas Copco Industrial Technique AB - 9839 0065 01
Service
Maintenance Instructions
Service Recommendations
Preventive maintenance is recommended at regular intervals. See the detailed information on preventive
maintenance. If the product is not working properly, take it out of service and inspect it.
If no detailed information about preventive maintenance is included, follow these general guide-
lines:
■Clean appropriate parts accurately
■Replace any defective or worn parts
Preventive Maintenance
Service interval overview
The table below shows the recommended service intervals for this tool, including what parts to service af-
ter 350, 700 and 1000 working hours.
The 1 000 hours service must only be carried out by authorized workshop or qualified service technician.
350 hours service 700 hours service 1 000 hours service
Inspect tool visually Inspect tool visually Inspect tool visually
Change oil Change oil Change oil
Clean filters Clean filters Clean filters
Service turbine
Service spindle
Service instructions
Changing oil
WARNING Risk of severe injury
Air under pressure can cause injury.
►Always shut off the air supply when not in use or before any adjustments.
►Drain the hose of air pressure and disconnect the tool from air supply when not in use or before
any adjustments.
►Always use the correct hose size and air pressure for the tool.
Required tools:
■Vice
■Screwdriver TX20
■Torque wrench
Spare parts
■Service kit including oil syringe filled with 7ml Turbine Gearbox Oil 32
(available to order from Atlas Copco).
Torque converter
■3 Nm = 2.2 ftlb
■6 Nm = 4.4 ftlb

GTG25 F120-13 EN Service
© Atlas Copco Industrial Technique AB - 9839 0065 01 19
Instructions
1. Connect the tool to the air supply (if not already connected).
Always lock auto-balancer with applicable part before running the tool.
Run the tool at idle speed for 60 seconds.
2. Disconnect the compressed air supply hose from the tool.
3. Remove the support handle from the tool.
4. Place the tool in a horizontal and stable position. Remove the spindle screw.
5. Remove the oil plug. Keep the tool in a horizontal position.
Drain the oil from the tool for at least 30 seconds.
6. Fit the spindle screw in position and tighten with recommended torque.
7. Place the tool in a vice in a vertical position with the oil filling hole downwards. Fill the tool with 7 ml
Turbine Gearbox Oil 32 using an oil syringe (included in the service kit)
Make sure that the tool is filled with oil within the recommended range. High oil level will cause
overheating, while low oil level can cause gear damage over time.
8. Clean the magnet on the oil plug from oil and particles using a clean lint-free cloth.
Fit the oil plug in position and tighten with recommended torque.

Service EN GTG25 F120-13
20 © Atlas Copco Industrial Technique AB - 9839 0065 01
Cleaning the fine air filter
Required tools:
■Vice
■Torque wrench
■Screwdriver
■Blow gun
Spare parts: At 1000 hours service the filter shall be replaced.
Instructions
1. Position the tool in a vice.
Remove the four screws from the handle using a torx screwdriver.
2. Remove the handle from the motor housing.
Remove the fine air filter from the valve housing.
Clean the fine air filter using a blow gun.
Replace the fine air filter if any damage or malfunction is detected.
Fit the cleaned or the new fine air filter in the valve housing.
Proceed with caution not to release the over speed shut- off mechanism.
3. Fit the handle to the motor housing.
Tighten the four screws in the handle to recommended torque.