AG 125-A22

About this documentation

• Read this documentation before initial operation or use. This is a prerequisite for safe, trouble-free handling and use of the product.
  
• Observe the safety instructions and warnings in this documentation and on the product.
  
• Always keep the operating instructions with the product and make sure that the operating instructions are with the product when it is given to other persons.
  

Explanation of symbols used

Warnings

Warnings alert persons to hazards that occur when handling or using the product. The following signal words are used:

Symbols in the documentation

The following symbols are used in this document:

	Read the operating instructions before use.
	Instructions for use and other useful information
	Dealing with recyclable materials
	Do not dispose of electric equipment and batteries as household waste

Symbols in the illustrations

The following symbols are used in illustrations:

	These numbers refer to the corresponding illustrations found at the beginning of these operating instructions
	The numbering reflects the sequence of operations shown in the illustrations and may deviate from the steps described in the text
	Item reference numbers are used in the overview illustrations and refer to the numbers used in the product overview section
	This symbol is intended to draw special attention to certain points when handling the product.

Product-dependent symbols

Symbols on the product

The following symbols are used on the product:

	Wear eye protection
	Rated speed
	Revolutions per minute
	Revolutions per minute
	Diameter
	Wireless data transfer
	Hilti Li-ion battery type series used. Observe the information given in the section headed Intended use .

Product information

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

  Angle grinder	AG 125-A22
  Generation	02
  Serial no.

Declaration of conformity

We declare, on our sole responsibility, that the product described here complies with the applicable directives 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 | 86916 Kaufering, Germany

Safety instructions

General power tool safety warnings

WARNING
Read all safety warnings and all instructions. Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
Work area safety

• Keep work area clean and well lit. Cluttered or dark areas invite accidents.
  
• Do not operate power tools in explosive atmospheres, such as in the presence of flammable liquids, gases or dust. Power tools create sparks which may ignite the dust or fumes.
  
• Keep children and bystanders away while operating a power tool. Distractions can cause you to lose control.
  

Electrical safety

• Avoid body contact with earthed or grounded surfaces, such as pipes, radiators, ranges and refrigerators. There is an increased risk of electric shock if your body is earthed or grounded.
  
• Do not expose power tools to rain or wet conditions. Water entering a power tool will increase the risk of electric shock.
  

Personal safety

• 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.
  
• Use personal protective equipment. Always wear eye protection. Protective equipment such as dust mask, non-skid safety shoes, hard hat, or hearing protection used for appropriate conditions will reduce personal injuries.
  
• Prevent unintentional starting. Ensure the switch is in the off‐position before connecting to battery pack, picking up or carrying the tool. Carrying power tools with your finger on the switch or energising power tools that have the switch on invites accidents.
  
• 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.
  
• Do not overreach. Keep proper footing and balance at all times. This enables better control of the power tool in unexpected situations.
  
• Dress properly. Do not wear loose clothing or jewellery. Keep your hair, clothing and gloves away from moving parts. Loose clothes, jewellery or long hair can be caught in moving parts.
  
• If devices are provided for the connection of dust extraction and collection facilities, ensure these are connected and properly used. Use of dust collection can reduce dust-related hazards.
  

Power tool use and care

• Do not force the power tool. Use the correct power tool for your application. The correct power tool will do the job better and safer at the rate for which it was designed.
  
• Do not use the power tool if the switch does not turn it on and off. Any power tool that cannot be controlled with the switch is dangerous and must be repaired.
  
• Disconnect the battery pack from the power tool before making any adjustments, changing accessories, or storing power tools. Such preventive safety measures reduce the risk of starting the power tool accidentally.
  
• Store idle power tools out of the reach of 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.
  
• Maintain power tools. 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.
  
• Keep cutting tools sharp and clean. Properly maintained cutting tools with sharp cutting edges are less likely to bind and are easier to control.
  
• Use the power tool, accessories and tool bits etc. in accordance with these instructions, taking into account the working conditions and the work to be performed. Use of the power tool for operations different from those intended could result in a hazardous situation.
  

Battery tool use and care

• 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.
  
• Use power tools only with specifically designated battery packs. Use of any other battery packs may create a risk of injury and fire.
  
• 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.
  
• 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.
  

Service

• Have your power tool serviced by a qualified repair person using only identical replacement parts. This will ensure that the safety of the power tool is maintained.
  

Safety warnings common for grinding, sanding, wire brushing, polishing or abrasive cutting-off operations:

• This power tool is intended to function as a grinder or cut-off tool. Read all safety warnings, instructions, illustrations and specifications provided with this power tool. Failure to follow all instructions listed below may result in electric shock, fire and/or serious injury.
  
• Operations such as sanding, wire brushing or polishing are not recommended to be performed with this power tool. Operations for which the power tool was not designed may create a hazard and cause personal injury.
  

• Do not use accessories which are not specifically designed and recommended by the tool manufacturer. Just because the accessory can be attached to your power tool, it does not assure safe operation.
  
• The rated speed of the accessory must be at least equal to the maximum speed marked on the power tool. Accessories running faster than their rated speed can break and fly apart.
  
• The outside diameter and the thickness of your accessory must be within the capacity rating of your power tool. Incorrectly sized accessories cannot be adequately guarded or controlled.
  
• Threaded mounting of accessories must match the grinder spindle thread. For accessories mounted by flanges, the arbour hole of the accessory must fit the locating diameter of the flange. Accessories that do not match the mounting hardware of the power tool will run out of balance, vibrate excessively and may cause loss of control.
  
• Do not use a damaged accessory. Before each use inspect the accessory such as abrasive wheels for chips and cracks, backing pad for cracks, tear or excess wear, wire brush for loose or cracked wires. If power tool or accessory is dropped, inspect for damage or install an undamaged accessory. After inspecting and installing an accessory, position yourself and bystanders away from the plane of the rotating accessory and run the power tool at maximum no-load speed for one minute. Damaged accessories will normally break apart during this test time.
  
• Wear personal protective equipment. Depending on application, use face shield, safety goggles or safety glasses. As appropriate, wear dust mask, hearing protectors, gloves and workshop apron capable of stopping small abrasive or workpiece fragments. The eye protection must be capable of stopping flying debris generated by various operations. The dust mask or respirator must be capable of filtrating particles generated by your operation. Prolonged exposure to high intensity noise may cause hearing loss.
  
• Keep bystanders a safe distance away from work area. Anyone entering the work area must wear personal protective equipment. Fragments of workpiece or of a broken accessory may fly away and cause injury beyond immediate area of operation.
  

• Hold the power tool by insulated gripping surfaces only, when performing an operation where the cutting tool 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.
  

• Position the cord clear of the spinning accessory. If you lose control, the cord may be cut or snagged and your hand or arm may be pulled into the spinning accessory.
  
• Never lay the power tool down until the accessory has come to a complete stop. The spinning accessory may grab the surface and pull the power tool out of your control.
  
• Do not run the power tool while carrying it at your side. Accidental contact with the spinning accessory could snag your clothing, pulling the accessory into your body.
  
• Regularly clean the power tool’s air vents. The motor’s fan will draw the dust inside the housing and excessive accumulation of powdered metal may cause electrical hazards.
  
• Do not operate the power tool near flammable materials. Sparks could ignite these materials.
  

• Do not use accessories that require liquid coolants. Using water or other liquid coolants may result in electrocution or shock.
  

Kickback and related warningsKickback is a sudden reaction to a pinched or snagged rotating wheel, backing pad, brush or any other accessory. Pinching or snagging causes rapid stalling of the rotating accessory which in turn causes the uncontrolled power tool to be forced in the direction opposite of the accessory’s rotation at the point of the binding.
For example, if an abrasive wheel is snagged or pinched by the workpiece, the edge of the wheel that is entering into the pinch point can dig into the surface of the material causing the wheel to climb out or kick out. The wheel may either jump toward or away from the operator, depending on direction of the wheel’s movement at the point of pinching. Abrasive wheels may also break under these conditions.
Kickback is the result of power tool misuse and/or incorrect operating procedures or conditions and can be avoided by taking proper precautions as given below.

• Maintain a firm grip on the power tool and position your body and arm to allow you to resist kickback forces. Always use auxiliary handle, if provided, for maximum control over kickback or torque reaction during start-up. The operator can control torque reactions or kickback forces, if proper precautions are taken.
  
• Never place your hand near the rotating accessory. Accessory may kickback over your hand.
  
• Do not position your body in the area where power tool will move if kickback occurs. Kickback will propel the tool in direction opposite to the wheel’s movement at the point of snagging.
  
• Use special care when working corners, sharp edges etc. Avoid bouncing and snagging the accessory. Corners, sharp edges or bouncing have a tendency to snag the rotating accessory and cause loss of control or kickback.
  
• Do not attach a saw chain woodcarving blade or toothed saw blade. Such blades create frequent kickback and loss of control.
  

Safety warnings specific for grinding and abrasive cutting-off operations:

• Use only wheel types that are recommended for your power tool and the specific guard designed for the selected wheel. Wheels for which the power tool was not designed cannot be adequately guarded and are unsafe.
  
• The grinding surface of centre depressed wheels must be mounted below the plane of the guard lip. An improperly mounted wheel that projects through the plane of the guard lip cannot be adequately protected.
  
• The guard must be securely attached to the power tool and positioned for maximum safety, so the least amount of wheel is exposed towards the operator. The guard helps to protect the operator from broken wheel fragments, accidental contact with wheel and sparks that could ignite clothing.
  
• Wheels must be used only for recommended applications. For example: do not grind with the side of cut-off wheel. Abrasive cut-off wheels are intended for peripheral grinding, side forces applied to these wheels may cause them to shatter.
  
• Always use undamaged wheel flanges that are of correct size and shape for your selected wheel . Proper wheel flanges support the wheel thus reducing the possibility of wheel breakage. Flanges for cut-off wheels may be different from grinding wheel flanges.
  
• Do not use worn down wheels from larger power tools. Wheel intended for larger power tool is not suitable for the higher speed of a smaller tool and may burst.
  

Additional safety warnings specific for abrasive cutting-off operations:

• Do not "jam" the cut-off wheel or apply excessive pressure. Do not attempt to make an excessive depth of cut. Overstressing the wheel increases the loading and susceptibility to twisting or binding of the wheel in the cut and the possibility of kickback or wheel breakage.
  
• Do not position your body in line with and behind the rotating wheel. When the wheel, at the point of operation, is moving away from your body, the possible kickback may propel the spinning wheel and the power tool directly at you.
  
• When wheel is binding or when interrupting a cut for any reason, switch off the power tool and hold the power tool motionless until the wheel comes to a complete stop. Never attempt to remove the cut-off wheel from the cut while the wheel is in motion otherwise kickback may occur. Investigate and take corrective action to eliminate the cause of wheel binding.
  
• Do not restart the cutting operation in the workpiece. Let the wheel reach full speed and carefully re-enter the cut. The wheel may bind, walk up or kickback if the power tool is restarted in the workpiece.
  
• Support panels or any oversized workpiece to minimize the risk of wheel pinching and kickback. Large workpieces tend to sag under their own weight. Supports must be placed under the workpiece near the line of cut and near the edge of the workpiece on both sides of the wheel.
  
• Use extra caution when making a "pocket cut" into existing walls or other blind areas. The protruding wheel may cut gas or water pipes, electrical wiring or objects that can cause kickback.
  

Additional safety instructions

Personal safety

• Only use the product if it is in perfect working order.
  
• Never tamper with or modify the tool in any way.
  
• Avoid touching rotating parts – risk of injury!
  
• Wear protective gloves also when changing the accessory tool. Touching the accessory tool presents a risk of injury (cuts or burns).
  
• Before starting work, check the hazard class of the dust that will be produced when working. Use an industrial vacuum cleaner with an officially approved protection class in compliance with the locally applicable dust protection regulations. Dust from materials such as lead-based paint, certain types of wood and concrete/masonry/stone containing quartz, minerals or metal may be harmful to health.
  
• Make sure that the workplace is well ventilated and, where necessary, wear a respirator appropriate for the type of dust generated. Contact with or inhalation of the dust may cause allergic reactions and/or respiratory or other diseases among operators or bystanders. Certain kinds of dust are classified as carcinogenic such as oak and beech dust, especially in conjunction with additives for wood conditioning (chromate, wood preservative). Material containing asbestos may be handled only by specialists.
  
• Take breaks between working and do physical exercises to improve the blood circulation in your fingers. Exposure to vibration during long periods of work can lead to disorders of the blood vessels and nervous system in the fingers, hands and wrists.
  

Electrical safety

• Before beginning work, check the working area for concealed electric cables or gas and water pipes. External metal parts of the power tool may give you an electric shock if you damage an electric cable accidentally.
  

Using and handling power tools with care

• Do not use cutting discs for grinding.
  
• Tighten the accessory tool and flange securely. If the accessory tool and flange are not tightened securely, the accessory tool may work loose from the spindle due to the braking effect of the motor after switching off.
  
• Comply with the manufacturer's instructions for handling and storing grinding discs.
  

Battery use and care

• Observe the special regulations and instructions applicable to the transport, storage and use of Li-ion batteries.
  
• Do not expose batteries to high temperatures, direct sunlight or fire.
  
• Do not disassemble, crush or incinerate batteries and do not subject them to temperatures over 80 °C.
  
• Do not use or charge batteries that have suffered mechanical impact, have been dropped from a height or show signs of damage. In this case, always contact your Hilti  Service .
  
• If the battery is too hot to touch it may be defective. In this case, place the product in a non-flammable location, well away from flammable materials, where it can be kept under observation and allowed to cool down. In this case, always contact your Hilti  Service .
  

Overview of the product

1. Guard release button
   
2. Spindle lockbutton
   
3. Air vents
   
4. Release button with additional function (charge status display activation)
   
5. Battery
   
6. Switch-on interlock release button
   
7. On/off switch
   
8. Vibration-absorbing side handle
   
9. Spindle
   
10. Standard guard
    
11. Clamping flange with O-ring
    
12. Abrasive cutting disc / abrasive grinding disc
    
13. Clamping nut
    
14. Kwik lock clamping nut (optional)
    
15. Wrench
    

Intended use

The product described is a hand-held cordless angle grinder. It is designed to be used for cutting and grinding metals and mineral materials, and for drilling tiles without use of water. It can be used only for dry grinding / cutting.

• The power tool may be used for cutting, slitting and grinding mineral materials only when equipped with the corresponding guard (optional accessory).

• A dust removal hood together with a suitable Hilti vacuum cleaner must be used for working on mineral materials such as concrete or stone.

• Use only Hilti Li‑ion batteries of the B 22 series with this product.
  
• Use only Hilti battery chargers of the C4/36 series for charging these batteries.
  

Items supplied

Angle grinder, side handle, standard guard, front cover, clamping flange, clamping nut, wrench, operating instructions.
Other system products approved for use with this product can be found at your local Hilti Store or online at: www.hilti.group | USA: www.hilti.com

Temperature-dependent motor protection

The temperature-dependent motor protection system monitors current input and motor temperature and thus prevents the power tool overheating.
If the motor is overloaded through application of excessive working pressure, the power tool’s performance drops noticeably or it may stall completely.
If the power tool stalls or slows significantly due to overloading, release the pressure applied to the tool and then allow it to run under no load for approx. 30 seconds.

Guard with front cover

When grinding with straight grinding discs and cutting with cutting discs in metalworking applications, use the standard guard with front cover.

DC-EX 125/5"C compact dust hood for cutting (accessory)

When cutting mineral materials with diamond cutting discs, use the DC-EX 125/5" C compact hood.
CAUTION Use of this hood for working on metal is prohibited.

DG-EX 125/5" dust hood for grinding (accessory)

The grinding system is suitable only for occasional use with diamond cup wheels for grinding mineral materials.
CAUTION Use of this hood for working on metal is prohibited.

Li-ion battery charge status display

The charge status of the Li‑ion battery is displayed after one of the two battery release buttons is pressed.

Status	Meaning
4 LEDs light.	Charge status: 75 % to 100 %
3 LEDs light.	Charge status: 50 % to 75 %
2 LEDs light.	Charge status: 25 % to 50 %
1 LED lights up.	Charge status: 10 % to 25 %
1 LED blinks.	Charge status: < 10 %

Noise information and vibration values in accordance with EN 60745

The sound pressure and vibration values given in these instructions were measured in accordance with a standardized test and can be used to compare one power tool with another. They can also be used for a preliminary assessment of exposure. The data given represents the main applications of the power tool. However, if the power tool is used for different applications, with different accessory tools, or is poorly maintained, the data can vary. This can significantly increase exposure over the total working period. An accurate estimation of exposure should also take into account the times when the tool is switched off, or when it is running but not actually being used for a job. This can significantly reduce exposure over the total working period. Identify additional safety measures to protect the operator from the effects of noise and/or vibration, for example: Maintaining the power tool and accessory tools, keeping the hands warm, organization of work patterns.
Noise information

Emission sound pressure level (LpA)	83 dB(A)
Uncertainty for the sound pressure level (KpA)	3 dB(A)
Sound (power) level (LWA)	94 dB(A)
Uncertainty for the sound power level (KWA)	3 dB(A)

Vibration informationOther applications, such as cutting, may produce vibration values that deviate from the given values.

Surface grinding with the vibration-absorbing side handle (ah,AG)	3.8 m/s²
Uncertainty (K)	1.5 m/s²

Inserting the battery

• Fit the battery and check that the battery is securely seated in the power tool.
  

Removing the battery

• Remove the battery.
  

Fitting the side handle

• Screw the side handle into one of the threaded bushings provided.
  

Fitting or removing the guard

• Observe the instructions for fitting the applicable guard.
  

Fitting the guard

1. Fit the guard onto the drive spindle collar so that the two triangular marks on the guard and on the power tool are in alignment.
   
2. Press the guard onto the drive spindle collar.
   
3. Press the guard release button.
   
4. Rotate the guard until it engages and the guard release button jumps back into its original position.
   

Adjusting the guard

• Press the guard release button and then rotate the guard until it engages in the desired position.
  

Removing the hood

1. Press the guard release button and then rotate the guard until the triangular marks on the guard and the power tool are in alignment.
   
2. Remove the guard.
   

Fitting or removing the front cover

1. Position the front cover with the closed side on the standard guard and push it on until it engages.
   
2. To remove it, release the catch for the front cover and then lift the front cover away from the standard guard.
   

Positioning the DC-EX 125/5"C dust hood (for cutting)

• Position the compact guard so that the on/off switch remains easily accessible and operable at all times.
  

Fitting and removing accessory tools

Fitting an accessory tool

1. Remove the battery.
   
2. Check that the O-ring is in place in the clamping flange and that it is undamaged.
   Result The O-ring is damaged.
   There is no O-ring in the clamping flange.
   
   • Fit a new clamping flange with O-ring.
     
3. Fit the clamping flange onto the drive spindle (keyed fit to prevent slipping/rotation).
   

4. Fit the accessory tool.
   

5. Screw on the clamping nut corresponding to the type of accessory tool fitted.
   
6. Press the spindle lockbutton and hold it in this position.
   
7. Use the pin wrench to tighten the clamping nut securely, then release the spindle lockbutton and remove the wrench.
   

Removing the accessory tool

1. Remove the battery.
   

2. Press the spindle lockbutton and hold it in this position.
   
3. Release the clamping nut by gripping it with the wrench and turning the nut counterclockwise.
   
4. Release the spindle lockbutton and remove the accessory tool.
   

Fitting an accessory tool secured with a Kwik lock nut

1. Remove the battery.
   
2. Clean the clamping flange and the quick-release clamping nut.
   
3. Fit the clamping flange onto the drive spindle.
   

4. Fit the accessory tool.
   
5. Screw on the Kwik lock nut until it is seated against the accessory tool.
   
   • The name Kwik lock should be visible when the nut is screwed on.
     
6. Press the spindle lockbutton and hold it in this position.
   
7. Turn the accessory tool firmly by hand in a clockwise direction until the Kwik lock nut is tightened securely and then release the spindle lockbutton.
   

Removing an accessory tool secured with a Kwik lock nut

1. Remove the battery.
   

2. Press the spindle lockbutton and hold it in this position.
   
3. Release the Kwik lock nut by turning it counterclockwise by hand.
   
4. If the Kwik lock nut cannot be released by turning it by hand, use a pin wrench to turn the nut in a counterclockwise direction.
   
   Never use a pipe wrench! A pipe wrench could damage the Kwik lock nut.
   
5. Release the spindle lockbutton and remove the accessory tool.
   

Fitting the core bit

1. Remove the battery.
   
2. Fit the side handle.
   
3. Fit the guard.
   
4. Place the core bit in position and tighten it hand-tight.
   
5. Press and hold down the arbor lockbutton.
   
6. Tighten the core bit with a suitable open-end wrench.
   
7. Then release the spindle lockbutton and remove the open-end wrench.
   

Grinding

Cutting

• When cutting, apply moderate feed pressure and do not tilt the power tool or the cutting disc (when working, hold at approx. 90° to the surface being cut).
  
  For best results when cutting profiles and square tube, start cutting at the smallest cross section.
  

Rough grinding

• Move the power tool to and fro while maintaining a 5° to 30° angle of attack and applying moderate pressure.
  
  • This will avoid overheating and discoloration of the workpiece and help ensure an even surface finish.
    

Switching on (tool equipped with switch-on safety interlock)

1. Push the safety lock forward.
   
   • The on/off switch is unlocked.
     
2. Press the on/off switch as far as it will go.
   
   • The power tool’s motor runs at no-load speed.
     

Switching off (tool equipped with switch-on safety interlock)

• Release the on/off switch.
  
  • The safety lock jumps automatically into the locked position.
    

Troubleshooting