DIN 980 V All-Metal Self-Locking Nuts

DIN 980 V All-Metal Self-Locking Nuts are hexagon nuts with an integrated metal locking function that generates prevailing torque on the mating thread. They are commonly referred to as all-metal self-locking nuts, prevailing torque lock nuts, or Stover-type lock nuts. Unlike nylon insert lock nuts, the DIN 980 V design uses no polymer insert, with the locking function formed directly within the metal nut.

The designation Form V refers to the specific construction of the nut. During manufacture, a defined portion of the threaded area is deformed from its normal geometry. When the nut is installed onto a mating bolt or stud, this deformed section creates additional friction and prevailing torque. The resulting interference helps resist loosening caused by vibration and dynamic loading while retaining the basic installation method of a conventional hexagon nut.

The all-metal construction makes DIN 980 V relevant to mechanical equipment, automotive applications, machinery, industrial assemblies, and other bolted joints where a metal prevailing torque solution is required. It is particularly useful where a polymer locking element is undesirable because of the application environment or assembly requirements.

DIN 980 V is a historical DIN designation that remains widely used in fastener purchasing and product identification. Related ISO standards include ISO 7042 for coarse-thread prevailing torque type all-metal hexagon nuts and ISO 10513 for fine-thread versions, although dimensional requirements should be checked against the specified standard rather than treating the standards as automatically interchangeable.