ProGroove™ Clamping Principles ProGroove System To change the cutting insert, place the wrench into the blade recess. The blade mouth is opened by turning through 90°. In this position, the wrench is self-locking, leaving both hands free for changing the cutting insert. The cutting insert is pressed against the rear seat in the blade mouth, releasing the wrench. The insert is accurately positioned and securely clamped. E96 widia.com