Screw Jacks carry the load (compression or tension) axially along their lead screw. Either the “lead nut” for rotating screw jacks or worm gear for translating screw jacks is the mating part, which converts the rotary motion to linear motion. These two parts are also wearing components. Should the mating thread on these components fail then the load would either be completely or partially unsupported by the screw jack. Although generally this is a remote risk for some applications extra safety features are required to ensure that the screw jack can support the load even in emergency situations.
A safety nut on a screw jack is an auxiliary nut, which follows the “lifting nut” on a rotating screw jack or the worm gear on a translating screw jack.
All Safety Nuts are BS EN 1570 Compliant