A headed externally threaded fastener whose threaded portion is of one nominal diameter with a single rectangular or triangular projection on the underside of the head.
NSN 5965-01-613-7134
NSN 6130-01-596-0540
NSN 5835-01-238-3381
NSN 5985-00-336-5813
NSN 5990-00-458-9643
NSN 6240-01-167-5040
NSN 6685-01-460-7032
NSN 5905-01-212-2792
NSN 2925-01-139-5144
NSN 6645-00-963-6354
NSN 5935-01-432-1166
NSN 6145-01-399-0467