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 5998-00-155-4666
NSN 6105-01-194-3647
NSN 5835-00-185-4919
NSN 5910-01-258-5312
NSN 5965-01-592-5391
NSN 6220-01-117-7619
NSN 6240-01-607-1480
NSN 6620-01-147-5615
NSN 5905-01-586-7613
NSN 6130-01-303-8144
NSN 5975-01-100-1822
NSN 6130-00-958-1064