Outside of collar tapered rather than distinctly shouldered
A soft metal or nonmetal sleeve, designed to mate with a pin-rivet. it may include an external wrenching facility which breaks off at a perdetermined torque to form a head.
NSN 6645-01-046-8849
NSN 6105-00-227-1412
NSN 6150-01-107-1010
NSN 6135-01-470-4077
NSN 6240-00-480-1558
NSN 6685-01-252-6418
NSN 6645-01-492-5304
NSN 5950-01-158-5041
NSN 5950-01-138-4640
NSN 5855-01-064-8961
NSN 6130-01-334-2153
NSN 6150-01-508-4509