One uses lock nuts to fasten roller bearings to adapter sleeves or directly to the shaft. However, they are also used to fasten other machine components. Lock nuts are also utilized when installing and removing roller bearings on withdrawal sleeves or bevelled centre pins. Depending on the application, one refers to self-locking, shaft, assembly or forcing nuts. To install or remove the lock nuts, one generally uses hook spanners and striking-face wrenches. Socket spanners can also be used for small lock nuts.

The designations of the lock nuts start with KM or HM. Lock nuts from the KM, KML, HM and HML series have four grooves on the outside diameter and are secured using series MB or MBL locking washers. Series HM 30 and HM 31 lock nuts have eight grooves in the outside diameter and eight front tapped holes. They are secured with series MS 30 or MS 31 securing rings (circlips).
Lock nuts with an H suffice are additionally provided with continuous tapped holes for erection bolts.