Designed to get into hollow forms for under cutting and cleaning up.
The HSS 12mm tip is made from cryo HSS and keeps its edge for a long time.
The tool comes with a torx key and round bar tip holder for sharpening the tip.
Simply screw the tip on the holder and then sharpen in a battery drill on a diamond file.
Avoid a grinder as this would shorten its life by grinding too much away.