June 26, 2012
PEM® nylon insert, self-locking fasteners from PennEngineering® provide a reusable, nonmetallic prevailing torque thread lock to prevent threaded mating hardware from loosening in service because of vibration or other application-related forces. Their trademarked blue nylon hexagonal locking element (black for metric types) helps eliminate potential galling, lubricant requirements, and the use of chemical locking methods or patches.
Types include PL (steel) and PLC PEMHEX® (stainless steel) self-clinching fasteners and CFN steel broaching fasteners. All install permanently in thin metal sheets, and their reliable threads accommodate mating hardware during final attachment of components.
The thread-locking performance of the PL and PLC fasteners is equivalent to applicable NASM25027 specifications. A knurled collar receives the installation force and resists torque, exhibiting spin resistance that exceeds the torque that can be exerted by the self-locking feature. Both the self-clinching shank and undercut contribute to high pushout values. They can install in aluminum or steel sheets as thin as 0.040 to 0.070 in. and are offered in thread sizes from #4-40 through #10-32 and M3 through M5.
The CFN broaching fasteners are suitable for thinner-sheet, close-to-edge applications. Upon installation, their broaching knurl creates a firm, interference-type fit resistant to rotation. The fasteners can be installed in sheets as thin as 0.040 in. and are available in thread sizes #4-30 and M3.