FIELD: grinding equipment. SUBSTANCE: jawbreaker has side walls and two opposite jaws. One of jaws is positioned for reciprocation toward and from other jaw. Other jaw is attached through attachment device so as to be detached from front end wall of jawbreaker. Attachment device is provided with tightening member extending through side wall of jawbreaker. Front end wall has protrusion extending toward immovable jaw. Attachment device has at least one wedge, whose one surface is in opposed relation to immovable jaw surface and other surface is in opposed relation to protrusion in front end wall of jawbreaker. Wedge is positioned for displacement toward and from both opposite surfaces by means of tightening member. Immovable jaw may be replaced. EFFECT: increased efficiency and simplified construction. 6 cl, 4 dwg
