4820-01-721-6608

A cylindrical item which may have wrenching and/or driving facilities and/or shoulders. It is designed to be inserted in a drilled, tapped or a pretapped hole, or molded or pressed into soft material to reduce the size of a tapped hole; to provide threads; to add strength, and/or to prevent stripping. It is one of the following: (1) a one-piece, flanged or unflanged, internally threaded item which may have external threads, and/or serrations around the periphery of the collar, designed to engage a serrated lock ring which is not included with the item; (2) a one-piece precision coiled wire; (3) a two-piece item consisting of an internally threaded cylinder and a mating externally threaded part; or (4) a one-piece internally threaded item whose outside diameter is tapered and/or knurled and/or with fin(s). The internal thread of the item may have a locking feature. Excludes:items having a sleeve on on its under portion which can be clinched or crimped. Excludes:bushing,machine thread; nut,plain,knurled; nut,plain,round; nut,plain,clinch and nut,self-locking,clinch. See also nut,plain,plate

restrictor assy part name assigned by controlling agency, an item that supports subsafe critical systems and requires objective quality evidence that quality assurance requirements have been met, including certification of tests for hydrostatic and/or operational testing and item serialization traceable to the certifications during initial procurement and any subsequent repairs. government source inspection is involved reference number differentiating characteristics, zzzy criticality code justification