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GX 90-WF

Original operating instructions

Information about the operating instructions

About these operating instructions

  • Read these operating instructions before the product is used or operated for the first time. This is a prerequisite for safe, trouble-free handling and use of the product.
  • Observe the safety instructions and warnings in these operating instructions and on the product.
  • Always keep the operating instructions with the product and make sure that the product is accompanied by these operating instructions only, when the product is given to other persons.

Explanation of symbols


Warnings alert persons to hazards that occur when handling or using the product. The following signal words are used:
  • Draws attention to imminent danger that will lead to serious personal injury or fatality.
  • Draws attention to a potential threat of danger that can lead to serious injury or fatality.
  • Draws attention to a potentially dangerous situation that could lead to personal injury or damage to the equipment or other property.

Symbols in the operating instructions

The following symbols are used in these operating instructions:
Image alternative Comply with the operating instructions
Image alternative Instructions for use and other useful information
Image alternative Dealing with recyclable materials
Image alternative Do not dispose of electric equipment and batteries as household waste
Image alternative Hilti Li‑ion battery
Image alternative Hilti charger

Symbols in illustrations

The following symbols are used in illustrations:
Image alternative These numbers refer to the illustrations at the beginning of these operating instructions.
Image alternative The numbering reflects the sequence of operations shown in the illustrations and may deviate from the steps described in the text.
Image alternative Item reference numbers are used in the overview illustration and refer to the numbers used in the key in the product overview section.
Image alternative These characters are intended to specifically draw your attention to certain points when handling the product.

Product-dependent symbols

Additional symbols

The following symbols can be used additionally in this documentation or on the product:
Image alternative General warning
Image alternative Wear eye protection
Image alternative Wear hearing protection
Image alternative Wear a hard hat
Image alternative Wear protective gloves
Image alternative The product supports near-field communication (NFC) technology compatible with iOS and Android platforms.
Image alternative Li-ion battery
Image alternative Never use the battery as a striking tool.
Image alternative Do not drop the battery. Never use a battery that has suffered an impact or is damaged in any other way.

Product information

Image alternative products are designed for professional users and only trained, authorized personnel are permitted to operate, service and maintain the products. This personnel must be specifically informed about the possible hazards. The product and its ancillary equipment can present hazards if used incorrectly by untrained personnel or if used not in accordance with the intended use.
The type designation and serial number are printed on the rating plate.
  • Write down the serial number in the table below. You will be required to state the product details when contacting Hilti Service or your local Hilti organization to inquire about the product.
    Product information
    GX fastening tool
    GX 90-WF
    Serial no.

Declaration of conformity

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The manufacturer declares, on his sole responsibility, that the product described here complies with the applicable legislation and standards. A copy of the declaration of conformity can be found at the end of this documentation.
The technical documentation is filed here:
Hilti Entwicklungsgesellschaft mbH | Tool Certification | Hiltistrasse 6 | D-86916 Kaufering, Germany


Safety instructions

Requirements to be met by users
  • The tool is intended for professional use.
  • The tool may be operated, serviced and repaired only by authorized, trained personnel. This personnel must be informed of any special hazards that may be encountered.
Personal safety
  • Stay alert, watch what you are doing and use common sense when operating a direct fastening tool. Do not use the tool when you are tired or under the influence of drugs, alcohol or medication. Take a break if you experience pain or feel unwell. A moment of inattention while operating tools may result in serious personal injury.
  • Avoid unfavorable body positions. Make sure you work from a safe stance and stay in balance at all times.
  • Wear non-skid shoes.
  • Never point the tool toward yourself or other persons.
  • Never press the nose of the tool against your hand or other part of your body, or against another person. Do not, under any circumstances, position your hand or other part of your body in the vicinity of the nosepiece. Pressing the nosepiece against a part of the body can lead to severe injury, due to unintentional actuation and firing of the fastener.
  • Do not place your free hand directly behind the material being fastened.
  • Do not position your free hand in the vicinity of the nosepiece.
  • Keep other people away from the working area, especially children.
  • Keep the arms slightly bent while operating the tool (do not straighten the arms).
  • Both the user and any other persons in the vicinity must wear suitable personal protective equipment including adequate eye protection, ear protectors and a hard hat.
Careful handling and use of direct fastening tools.
  • Never leave a loaded tool unattended.
  • Remove the gas can from the tool before transporting the tool.
  • Always unload the tool (remove the battery, gas can and nails) before cleaning, servicing, and repair work, before a break in your work, and for storing the tool.
  • Store unused gas cans and tools that are not currently being used in a dry place where they are not exposed to moisture and excessive temperatures.
  • To ensure that the tool functions faultlessly and as intended, always check the tool and accessories for possible damage before use. Check that moving parts function faultlessly, without sticking, and that no parts are damaged. All parts must be fitted correctly and fulfill all conditions necessary for correct operation of the tool. Damaged protective devices and parts that are not included in the service package available as an accessory (see the section headed "Care of the tool") must be properly repaired or replaced by Hilti Service unless otherwise stated in the operating instructions.
  • Always hold the tool firmly when making a fastening. This will reduce the possibility of the fastener being deflected by the material into which it is driven.
  • Never attempt to re-drive a fastener. Never drive a fastener on top of another previously-driven fastener. This may lead to fastener breakage and jamming.
  • Always observe the application guidelines. For more information, consult the Hilit Fastening Technology Manual.
  • Do not pull the nosepiece back with your hand or with an object. Under certain circumstances, this could make the tool ready to fire. When the tool is ready to fire, fasteners or the piston could be driven inadvertently into parts of the body.
  • Make sure that the workplace is well lit.
  • Operate the tool only in well ventilated working areas.
  • Drive fasteners only into wood and other suitable wood materials (see "Intended use"): Driving a fastener into other materials may cause the fastener to break, shatter or to be driven right through.
  • Before driving fasteners, check that no one is present immediately behind or below the working surface.
  • Keep the workplace tidy. Objects which could cause injury should be removed from the working area. Untidiness at the workplace can lead to accidents.
  • Keep the grips dry, clean and free from oil and grease.
  • Take the influences of the surrounding area into account. Do not expose the appliance to rain or snow and do not use it in damp or wet conditions. Do not use the appliance where there is a risk of fire of explosion.
  • Concealed electrical cables or gas and water pipes present a serious hazard if damaged while you are working. Therefore, check the working area before you begin, e.g. using a metal detector. External metal parts of the appliance or machine may become live, for example, when an electric cable is damaged accidentally.
  • Only hold the tool by its insulated gripping surfaces if carrying out work where the insert tool may come into contact with concealed wiring. Metal parts of the power tool can also become live, resulting in electric shock, if contact is made with a live cable.
Thermal safety rules
  • If the tool overheats, remove the gas can and allow the tool to cool down. Do not exceed the specified maximum fastener driving rate.
  • Always wear gloves if cleaning or maintenance has to be carried out before the tool has been allowed to cool down.
Careful handling and use of gas cans.
  • Read the safety data sheet for the gas can for information about use, care and maintenance and first-aid measures.

Careful handling and use of batteries

  • Comply with the following safety instructions for the safe handling and use of Li-ion batteries. Failure to comply can lead to skin irritation, severe corrosive injury, chemical burns, fire and/or explosion.
  • Use only batteries that are in perfect working order.
  • Treat batteries with care in order to avoid damage and prevent leakage of fluids that are extremely harmful to health!
  • Do not under any circumstances modify or tamper with batteries!
  • Do not disassemble, crush or incinerate batteries and do not subject them to temperatures over 80 °C (176 °F).
  • Never use or charge a battery that has suffered an impact or been damaged in any other way. Check your batteries regularly for signs of damage.
  • Never use recycled or repaired batteries.
  • Never use the battery or a battery-operated power tool as a striking tool.
  • Never expose batteries to the direct rays of the sun, elevated temperature, sparking, or open flame. This can lead to explosions.
  • Do not touch the battery poles with your fingers, tools, jewelry, or other electrically conductive objects. This can damage the battery and also cause material damage and personal injury.
  • Keep batteries away from rain, moisture and liquids. Penetrating moisture can cause short circuits, electric shock, burns, fire and explosions.
  • Use only chargers and power tools approved for the specific battery type. Read and follow the relevant operating instructions.
  • Do not use or store the battery in explosive environments.
  • If the battery is too hot to touch, it may be defective. Put the battery in a place where it is clearly visible and where there is no risk of fire, at an adequate distance from flammable materials. Allow the battery to cool down. If it is still too hot to touch after an hour, the battery is faulty. Consult Hilti Service or read the document entitled "Instructions on safety and use for Hilti Li-ion batteries".
    Observe the special guidelines applicable to the transport, storage and use of lithium-ion batteries.
    Read the instructions on safety and use of Hilti Li-ion batteries that you can access by scanning the QR code at the end of these operating instructions.


Product overview

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  1. Tool body
  2. Grip
  3. Nosepiece
  4. Magazine
  5. Rating plate
  6. Gas can compartment
  7. Battery
  8. Air vents
  9. Casing cover
  10. Trigger
  11. Adjusting wheel
  12. Nail pusher
  13. Belt hook
  14. LED
  15. Adapter for surface protection
  16. Sliding sleeve

Intended use

The tool is for fastening wood to wood using specially manufactured fasteners. The tool is suitable for use with solid wood, laminated timber, plywood, chipboard materials (e.g. coarse oriented-strand board), fiberboard materials (e.g. medium density fiberboard), and veneer materials (e.g. Multiplex). The tool is intended for use by professionals in the timber construction industry. For usage recommendations, consult the Hilti Fastening Technology Manual.

The tool, gas can and fasteners form a single technical unit. This means that trouble-free fastening with this tool can be ensured only when it is used together with the Hilti nails and Hilti gas cans specially manufactured for it. The fastening and application recommendations made by Hilti apply only when these conditions are observed. The tool is for hand-held use only. Do not tamper with or attempt to make alterations to the machine.
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  • Use only Hilti lithium‑ion batteries of the B 7 series with this product.

  • For these batteries, use only the C 7 battery charger approved by Hilti . More information is available from your Hilti Store or from

Deep discharge protection

The tool has a hibernation mode to protect the Li-ion battery from deep discharge. The tool switches itself off completely, automatically, if unused for 120 minutes.
  • To restore operational readiness, briefly remove the battery and reinsert it (battery reset).

Items supplied

Power tool in case, battery, charger, cleaning cloth, operating instructions.
Other system products approved for use with this product can be found at your local Hilti Store or at:

System components for operating the tool

The following items are required to use the tool: Power tool, charged B 7 Li ion battery, GC 31 or GC 32 gas can and GX-WF nails for wood.

Technical data

Direct fastening tool

Nailing to squared timber
Weight (including battery)
3.7 kg
(8.2 lb)
384 mm x 134 mm x 381 mm
(15.1 in x 5.3 in x 15.0 in)
Power regulation
Maximum magazine capacity
75 pcs
Magazine angle
(0.6 rad)
Maximum fastener driving rate in continuous operation
1,200 h
Work with interruptions
up to 3 fastenings per second
Caliber (gas can)
40 g
(1.4 oz)
Operating / ambient temperature with GC 31 gas can
−5 ℃ … 45 ℃
(23 ℉ … 113 ℉)
Operating / ambient temperature with GC 32 gas can
−10 ℃ … 45 ℃
(14 ℉ … 113 ℉)
Nail length
50 mm … 90 mm
(2.0 in … 3.5 in)
Nail diameter
2.8 mm … 3.1 mm
(0.11 in … 0.12 in)

Lithium‑ion batteries

Battery operating voltage
7.2 V
Ambient temperature for operation
−17 ℃ … 60 ℃
Storage temperature
−20 ℃ … 40 ℃
Battery charging starting temperature
−10 ℃ … 45 ℃

Noise information and acceleration in accordance with EN 15895

The sound pressure and vibration values given in these instructions have been measured in accordance with a standardized test and may be used to compare one fastening tool with another. They may be used for a preliminary assessment of exposure. The data given represents the main applications of the fastening tool. However, if the fastening tool is used for different applications, with different accessories or is poorly maintained, the data may vary. This may significantly increase exposure over the total working period. An estimation of the level of exposure should also take into account the periods of time when the tool is not actually in use. This may significantly reduce exposure over the total working period. Prescribe additional safety measures to protect the operator from the effects of noise and/or vibration, such as: maintenance of the direct fastening tool and its additional equipment or accessories, keeping the hands warm, organization of work patterns.
Noise information
Emission sound pressure level at the workplace (LpA, 1s)
106 dB(A)
Peak sound pressure level at the workplace (LpC, peak)
138 dB (C)
Sound power level (LWA, 1S)
108 dB(A)
Uncertainty, noise (KpA)
2 dB(A)
Energy-equivalent acceleration (ahw, RMS(3))
Results, nail size 90x3.1 mm in solid spruce timber <2.5 m/s2

Before use

Inserting nails

Hazard due to use of the wrong fasteners Use of the wrong fasteners can lead to tool malfunctions and/or injuries.
  • In particular, make sure that you are using suitable fasteners collated at the correct angle in the magazine.
There is a retention spring in the bottom of the magazine. If the maximum number of fasteners in the magazine is exceeded, the last strip of nails to be inserted cannot be held back by this spring. Remove the strip of nails that was last inserted.
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  1. Insert the fasteners into the magazine from below, pointing in the right direction.
Injury due to inattention Inattention can result in your fingers being trapped.
  • Move the nail pusher carefully, pull it steadily back over the nails, until it snaps into place at the bottom end of the nail strip.
  1. Push the fasteners as far as they will go toward the nosepiece.
    The nail strip could suffer damage if the nail pusher is allowed to strike it with force. Do not allow the nail pusher to strike the nail strip with force.

Preparing the gas can

Risk of accident Risk of injury by escaping gas.
  • Gas from the gas can is harmful to the lungs, skin and eyes. Keep the metering valve away from your face and eyes.
  • The pressurized liquefied gas can escape and endanger you and others. Never remove the metering valve from a prepared gas can or a used gas can.
  • Transport lock for gas can.
    The gas can is fitted with a transport lock. Remove the lock before inserting the gas can into the tool.

Removing the transport lock

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  1. Lift the safety cap and metering valve off the gas can.
  2. Disconnect the safety cap from the metering valve.
  3. Insert the metering valve with the front hooking groove into the gas can notch.
    The metering valve has a front and a rear hooking groove.
  4. Press the rear hooking groove firmly over the lip of the gas can until the metering valve snaps into place on the can.

Inserting the gas can

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  1. Open the cover of the gas can compartment by pressing it upwards and to the rear.
  2. Push the gas can and metering valve into the red adapter.
  3. Close the cover by pressing it down with your thumb until the latch snaps into engagement.

Inserting the battery

Risk of damage Incorrect operation of the equipment can lead to damage.
  • Read the operating instructions for the C 7 charger for instructions on charging the battery and for further information about use and care of the battery.
A falling battery presents a hazard. If the battery is not secured correctly it may drop out and fall while the work is in progress.
  • Check that the battery is seated securely.
Risk of injury When inserting the battery, there is a risk of pinching the skin.
  • Take care when inserting the battery.
  1. Before inserting the battery, make sure that the battery contacts and the contacts in the tool are free of foreign bodies.
  2. From below, push the battery into the opening at the end of the grip until it snaps into place. The LED briefly lights up in green to signal that the tool is ready for use.
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  1. Charge the battery fully before using the tool for the first time.

Battery state of charge

Possible cause
Action to be taken
Green LED is on/flashes
  • The battery is ready for use.
  • Drop in battery voltage. Change the battery soon.
Red LED is on/flashes
  • Battery voltage is no longer adequate for operation of the tool. Change the battery.
  • Switch to the second battery, at the latest when the LED on the tool shows red. Recharge the battery immediately so that it is ready for reuse.
  • The battery is too cold (<-15 °C / <5 °F) or too hot (>60 °C / >140 °F) and the fan does not start. Remove the battery and allow it to warm up or cool down to the required temperature.
No signal
No LED lit up or flashing
  • The battery voltage is below the threshold value. Charge the battery.


Settings at the nosepiece

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  • You can control the penetration depth of the nails by changing the position of the nosepiece. Use the adjusting wheel for this purpose.

Protecting sensitive surfaces

Risk of injury You might inadvertently trigger a misfire.
  • Remove the battery and the gas can from the tool before installing or removing the surface protector.
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  • Use the adapter for surface protection when working on visible surfaces that are easily marked, for example building facades.
    The surface protection adapter reduces the possibility of the nosepiece leaving marks on the surface of the wood.

Unintentional firing safety device

  1. Never operate the product without the unintentional firing safety device (sliding sleeve).
  2. The tool has a safety device to prevent it from being triggered incorrectly. The sliding sleeve prevents the nosepiece from being pushed back deliberately or unknowingly. This prevents accidental releases.

Driving nails

You can drive nails only if there are more than 5 nails in the magazine.
Hold the tool securely. Avoid resilient materials.
Pull the trigger only after the tool has been fully pressed against the working surface.
Do not release the trigger until the nail has been driven fully into the material.
  1. Position the nosepiece on the working surface and press the tool against the surface until the nosepiece is fully compressed.
  2. Drive the fastener by pulling the trigger.
  3. Release the trigger and lift the tool completely clear of the surface.

Unloading the tool

Removing the battery

Store the battery in a cool and dry place. Never store the battery where it is exposed to direct sunlight or sources of heat, e.g. on heaters / radiators or behind glass. At the end of their useful life, batteries must be disposed of safely and correctly to avoid environmental pollution.
  1. Press both battery release buttons.
  2. Pull the battery downwards out of the power tool.

Removing the gas can

  1. Open the gas can compartment cover.
  2. Remove the gas can.
  3. Close the gas can compartment.

Unloading nail strips

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  1. Release the catch on the nail pusher by pressing the black button.
  2. Carefully allow the pusher to slide slowly toward the nosepiece until it stops.
  3. Allow the nails in the magazine to slide downwards.
  4. Press the internal pawl on the bottom end of the magazine. You can now completely remove the nails from the magazine.

Tool hook

Risk of injury A falling tool can injure you and/or others.
  • Make sure that the tool attached to the belt hook is secure.
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  • You can use the tool hook to hook the tool to your belt, a ladder, or a roof batten. Press the belt hook towards the tool in the direction of the longitudinal axis of the magazine. This releases the belt hook from its locked position and it can then be swung in or out.

Care and maintenance

Care and maintenance of the tool

The tool must be unloaded (remove the gas can and fastener from the tool) before carrying out cleaning or maintenance. Completely remove the battery, gas can and nail strip from the tool.
  1. Clean the outside of the power tool at regular intervals with a slightly damp cloth.
  2. Never operate the tool when the ventilation slots are blocked. Clean the ventilation slots carefully using a dry brush.
  3. Do not permit moisture or foreign objects to enter the interior of the tool or the battery.
  4. Remove the tool from its case and allow it to dry out if moisture has entered the tool. To do this, remove the battery and keep the gas can compartment cover at the rear in the open position.
  5. Always keep the grip surfaces of the appliance free from oil and grease.
  6. Do not use a spray, steam pressure cleaning equipment or running water for cleaning.
  7. Do not use cleaning agents containing silicone.
  8. Make sure that there is no oil or grease on the battery contacts.

Repair of the power tool

  • Regularly check all external parts of the tool for damage and check that all controls are in full working order. Do not operate the tool if parts are damaged or if controls are not in full working order.
    If damage occurs, have the tool repaired by Hilti Service only.

Cleaning the appliance

The tool needs regular maintenance and cleaning. We recommend that the tool is cleaned, at the latest, after making 40,000 fastenings. The tool should also be cleaned if malfunctions occur frequently, e.g. misfiring or firing without a nail being driven.
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  • Clean the power tool at regular intervals. Use only Hilti products or products of comparable quality for cleaning.
    • The required materials, tools, and documentation are available from Hilti as accessories.
    • You can have the necessary maintenance work carried out by Hilti . To do so, contact your local Hilti branch.

Cleaning the piston

Dirt and remains of the nail collation strip may hinder piston movement. Malfunctions occur increasingly, i.e. the tool is triggered but no fastener is driven. In this case, the piston should be cleaned as follows:
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  1. Remove the battery, the gas can and the fasteners from the tool.
  2. Use a screwdriver to push the piston back as far as it will go.
  3. Spray cleaning fluid generously into the tool nosepiece.
  4. First replace the battery and then the gas can.
  5. Pull the nail pusher back by hand and then trigger the tool five times, without driving fasteners, with the nosepiece pressed against a suitable surface (see the section headed "Intended use").
  6. Reload the fasteners and continue working with the tool in the usual way.
  7. If necessary, repeat steps 1-6.


Possible cause
Action to be taken
The tool is fired frequently without a fastener loaded
Working speed too high
  • Adhere to the maximum fastener driving rate.
The tool is not pressed fully against the working surface and/or the trigger is not pulled fully.
  • Press the tool fully into contact with the workpiece and do not release the trigger until the nail has been fully driven.
Tool has reached its target life of 40,000 fasteners driven.
Jammed piston
Irregular nail projections
Tool has reached its target life of 40,000 fasteners driven.
Hard and/or knotty wood
  • Change the nails or, if possible, use a different supporting material.
Empty gas can
Inadequate contact / no base material
Working speed too high
  • Adhere to the maximum fastener driving rate.
Incorrect piston position
Jammed piston (paper, nail or wood debris in the tool)
The tool doesn’t fire: Tool indicates that it is ready for use but when the trigger is pulled, tool does not fire
Tool not pressed fully against the surface
Nail jam
Nail jammed in the tool nosepiece
  • Remove the battery and the gas can.
  • Remove the jammed nail.
  • Use a screwdriver to push the piston all the way back.
Gas can capacity sufficient for < 1000 nails
Gas loss due to frequent unproductive pressing against the surface
  • Press the tool against the surface only when you intend to drive a fastener.
The cover of the gas can compartment will not close (gas can inserted).
Transport lock on gas can not removed
Nail driven in too far
Nosepiece too far back
Protruding nail
Nosepiece too far forward
Very flat application angle
  • Press the tool against the surface as close to a right angle as possible.
Tool slips out of position on the surface
Adapter for surface protection is fitted to the nosepiece
Fan does not start, LED flashes red
Battery too cold (<-15 °C) or too hot (>60 °C)
  • Remove the battery, warm it up or allow it to cool down.
  • Insert another battery.
The fan doesn’t start, no LED lights
The tool is in hibernation mode
If the problem remains: No battery power
  • Insert another battery.
  • Charge the battery.
Water or moisture in the tool
The fan does not start, the LED lights up in red
The battery voltage is not sufficient to operate the tool.
  • Insert another battery.
  • Charge the battery.
Fan does not start, LED shows green
Plug connector to the fan is disconnected
  • Remove the battery and the gas can.
  • Plug in the fan connector.
The fan connector is fitted correctly but the fan still doesn’t start.
  • Have the tool repaired by Hilti Service.
The fan is running, the tool does not fire
Empty gas can
Tool has reached its target life of 40,000 fasteners driven.
The tool can not be pressed against the work surface
Less than 5 nails in the magazine
  • Reload the nail strip.
Nails jammed
  • Remove the battery and the gas can.
  • N.B.: Do not carry out any maintenance work without fully unloading the tool.
  • Remove jammed nails.
Frequent transport malfunctions with nails in plastic strips
Damaged magazine strip
  • Hold the nail pusher firmly when operating.


Risk of injury due to incorrect disposal! Health hazards due to escaping gases or liquids.
  • DO NOT send batteries through the mail!
  • Cover the terminals with a non-conductive material (such as electrical tape) to prevent short circuiting.
  • Dispose of your battery out of the reach of children.
  • Dispose of the battery at your Hilti Store , or consult your local governmental garbage disposal or public health and safety resources for disposal instructions.
Image alternative Most of the materials from which Hilti products are manufactured can be recycled. The materials must be correctly separated before they can be recycled. In many countries, your old tools, machines or appliances can be returned to Hilti for recycling. Ask Hilti Service or your Hilti sales representative for further information.
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  • Do not dispose of power tools, electronic equipment or batteries as household waste!

Manufacturer’s warranty

  • Please contact your local Hilti representative if you have questions about the warranty conditions.

Further information

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For more information on operation, technology, environment and recycling, follow this link:
This link is also to be found at the end of the documentation, in the form of a QR code.