Fastening Alternatives to Adhesives or Rivets

SI® threaded inserts provide strong, reusable metal threads in plastics to allow for subsequent access to assemblies when required. These brass, stainless steel, or aluminum threaded inserts serve as practical alternatives to permanent joining methods, such as adhesives or rivets. Components can be removed and re-attached quickly and easily utilizing mating hardware.

Applications include computer and terminal boards; automotive and aerospace components; electronics, medical, and communications equipment; and others where plastic assemblies can benefit from permanently installed metal threads allowing for accessibility.

The product line includes ultrasonic/heat staking threaded inserts installed ultrasonically or with a thermal press; molded-in threaded inserts installed during the molding process; and press-in threaded inserts installed by pressing them into pre-molded or drilled holes.

SI threaded inserts are available in a variety of types and in a wide range of unified and metric thread sizes. Detailed specifications (Bulletin SI) and free parts drawings (PEM CAD Library) for the entire product line can be found at

Contact Michael J. Rossi, PennEngineering®, 5190 Old Easton Road, Danboro, PA 18916-1000 USA. Phones: 800-237-4736 or 215-766-8853; Fax: 215-766-0143. Web site:

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