Locknuts

Lock nuts are used to locate bearings and other components onto a shaft or adapter sleeve. They are also used for mounting bearings on tapered shaft seats and dismounting bearings from withdrawal sleeves. Lock nuts have to be secured to prevent unintentional loosening. This is done, either by a locking device that engages a key way in the shaft or key slot in the adapter sleeve, or by a locking mechanism integrated in the nut. Lock nuts with an integrated locking mechanism reduce the cost of the shaft as no key way is required. Installation is also quicker and easier because no separate locking device is necessary. However, the loosening torque requires more attention.

The product codes for lock nuts start with HM or KM.

KM, KML or HM, HML, and HMLL have four grooves on their outer diameter. By contrast, the HM 30.. and HM 31.. ranges have eight grooves on their outer diameter and eight thread bores for securing a locking clip. Different suffixes (letters) distinguish within the ranges. A distinction is made between H and HS designs.

• H = Lock nuts with the suffix H have additional thread bores right through them. This makes it possible to mount them with additional screws.
• HS = Lock nuts with the suffix HS have additional thread bores right through them and come with the relevant mounting screws.

The standard lock nut and washer is replaced by a KMFE, washer less nut or the standard lock nut HM30 is replaced by HME nut with a recessed outside diameter.