| 摘要 |
A torque-limited screw-threaded locking fastener comprises an externally threaded shank (41) and an internally threaded collar (20). At least one convolution of the shank threads (43) is non-circular. The collar (20) has a nut section (25) connected by a shear section (35) to a drive section (21). The shear section (35) fractures when a predetermined torque is exerted between the two sections (21,25). The nut section (25) has an external rib(s) (33) engageable by a swaging tool (60) to radially inwardly displace the rib (33) so as to displace nut section material into the non-circular convolution (45) whereby to lock the nut (25) to the shank (41) after the drive section (21) is torqued off. The swaging of the rib to a lesser radial dimension does not change the torque level which was applied when the drive section (21) was torqued off. <IMAGE> |
