PEM RT™ self-clinching free-running locknuts from PennEngineering® feature a modified thread angle enabling easier tightening of mating screws and superior vibration-resistant locking performance in thin metal assemblies. The modified thread formation allows mating screws to spin freely during the attachment process until clamp load is induced during the screw-tightening process.
The applied clamp load then engages the locknut’s vibration-resistant locking feature, which securely and reliably locks the screw in place. Compared with traditional locknuts, excellent joint clamp load remains consistent, even after many on/off cycles.
PEM RT™ self-clinching locknuts install into aluminum or steel sheets as thin as .030”/0.8mm and become permanent parts of an assembly. Upon their installation using a PEMSERTER® or other standard press, the back side of the host metal sheet for screw insertion will be flush or sub-flush and the assembly side will be flush or sub-flush ideally suiting sheet-to-sheet attachment applications.
These carbon steel locknuts can be specified with thread sizes from #4-40 through 5/16-18 and M3 through M6 and in a variety of shank lengths. Zinc plating finishes are available in standard colorless or optional yellow.
This graph represents the clamp load of the joint versus the amount of cycles during transverse vibration testing for an PEM RT® free-running locknut, a standard S nut, a split ring lock washer and Loctite Red 271.
Testing conditions: Transverse vibration testing. M6 thread size nuts, average of 30 pieces. Clamp load applied using metric property class 12.9 screws. Nuts tested until loss of clamp load or 2,000 cycles is reached.
(1) For maximum performance, we recommend that you use the maximum shank-length for your sheet thickness.