The deformation and expansion of the tool tip or piston striking surface is called "Mushrooming". This indicates that the steel has lost its properties.
1. Why Does It Happen?
- Overheating: If you strike the same spot for more than 15 seconds, friction heat exceeds 500°C. The steel loses its temper (softens).
- Insufficient Lubrication: Dry friction between the tool and bushing also increases heat.
2. How to Prevent It?
- Strike Duration: Follow the 15-second rule. If the rock doesn't break, don't persist; change the spot.
- Check: If mushrooming starts, grind off the deformed part. Otherwise, broken pieces will get stuck between bushings.