Operating instructions for Hilti AG 125-A22 Angle Grinder

Quick guide from the manual

The Hilti AG 125-A22 is a cordless angle grinder designed for professional abrasive cutting and grinding of metal and mineral materials. This document provides essential safety guidelines, setup instructions, and maintenance procedures. Always ensure the tool is switched off and the battery is removed before performing any adjustments or maintenance.

Device description

The tool features a spindle lock button, side handle, protective guard, and a battery interface. It is compatible with Hilti Li-ion batteries and requires specific chargers (C 4/36 series). The tool includes thermal protection to prevent motor overheating; if the tool slows down or stops, reduce the load and allow it to run at idle for 30 seconds.

Installation and setup

• Battery: Ensure the tool is switched off before inserting the battery. Check that contacts are clean.
• Side handle: Screw the side handle into one of the provided threaded bushings.
• Protective guard: Align the triangle marks on the tool and the guard, press onto the spindle neck, and rotate until it clicks into place.
• Disc installation: Use the spindle lock button only when the spindle is at a complete standstill. Ensure the O-ring in the clamping flange is present and undamaged. Tighten the clamping nut securely using the provided wrench.

Operation

Always use the side handle during operation. For rough grinding, an angle of 5° to 30° provides optimal results. When cutting, maintain a low feed rate and avoid tilting the disc. The switch includes a lock-on feature to prevent accidental startup.

Maintenance and safety

Regularly clean the ventilation slots with a dry brush. Do not allow foreign objects to enter the housing. If working with conductive materials (metal, carbon fiber), frequent cleaning is required. Do not use water sprays or steam cleaners. Always wear appropriate personal protective equipment, including safety glasses, ear protection, and a dust mask.

Troubleshooting

If the battery discharges faster than usual, allow it to warm to room temperature. If the tool does not start, check the battery charge level or if the tool has overheated. If all 4 LEDs flash, the tool has experienced a temporary overload or thermal protection has triggered; release the switch and allow the tool to cool.