PEM® S-RT™ Self-Clinching Locknuts comes with zinc plated finishing.

Press Release Summary:

PEM® S-RT™ Self-Clinching Locknuts comes with improved thread formations that enable mating screws to spin freely in attachment process. Offered with thread sizes ranging from #4-40 through 5/16-18 and M3 through M6 with different shank lengths, carbon steel nuts install into aluminum or steel sheets as thin as 0.8 mm. Units are compliant to RoHS standards.

Original Press Release:

New PEM® S-RT™ Self-Clinching Free-Running Locknuts with Modified Threads Enable Easier Tightening of Mating Screws and Vibration-Resistant Locking Performance

New PEM® S-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 S-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.

Detailed technical literature (PEM® Bulletin RT), individual fastener drawings, and CAD models for these RoHS-compliant fasteners can be downloaded at

Founded in 1942 and celebrating 75 years, PennEngineering (Danboro, PA, USA) is a global leader in the fastening industry with technical and manufacturing facilities in North America, Europe, and Asia supported by a global engineering-focused sales force and a worldwide network of authorized distributors.

For more information, visit, email, or contact Michael J. Rossi, PennEngineering®, 5190 Old Easton Road, Danboro, PA 18916-1000 USA. Tel: +1-800-237-4736 (toll-free in the U.S.) and +1-215-766-8853.

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