Locknuts are suitable for locating bearings on cylindrical and tapered shafts, or on adapter sleeves, and for mounting and dismounting of bearings on withdrawal sleeves. Locknuts have four or eight evenly spaced slots on the circumference. As a result, they can be tightened particularly easily with striking-face or hook wrenches. The locknuts are secured by means of tab washers or retaining brackets. Precision locknuts Precision locknuts are bearing accessories for screw drives. They are used to achieve a defined axial preload in axial angular contact ball bearings for screw drives and axial/radial roller bearings for screw drives. Precision locknuts are also used in other applications where high axial forces must be supported and high axial runout accuracy and rigidity are required. Precision locknut designs: axial locking by segments (design AM) securing by radial locking pegs (designs ZM, ZMA).