This part of ISO 10071 specifies interchangeability dimensions and tolerances, in millimetres, for ball-lock punches for heavy duty. It is applicable to ball-lock punches with shank diameter sizes from 10 mm up to including 40 mm, in round, square, rectangular and oblong shapes, for punching holes in steel sheets or other materials the thickness of which is less than 8 mm. This part of ISO 10071 also gives examples related to materials and hardness, and specifies the designation of ball-lock punches for heavy duty.