Vibration dampened drill bit has a hard metal bit held in a plastic support grip via a profiled grip end and with an outer steel grip sleeve

摘要

A vibration dampened drill bit, e.g. for drilling circuit boards, has a hard metal bit (22) with a hard metal shaft (24) which has a grip profile (26) embedded in a plastic support grip (42). A steel grip sleeve (44) has a recessed fit around the plastic grip over most of the length of the grip. The plastic has good thermal conductivity and can be fibre reinforced.