Bolt carriage square neck button head; black steel; 1/4 in. Dia, 3-1/2 in. Long
No other part numbers with same form, fit, and function found.
A headed externally threaded fastener whose threaded portion is of one nominal diameter, with a square neck directly beneath the head.
NSN 6685-00-914-2345
NSN 6685-01-268-1724
NSN 6220-01-459-4631
NSN 5935-01-594-3702
NSN 5905-01-197-5427
NSN 5965-00-529-0602
NSN 5920-01-245-8510
NSN 5999-01-188-8316
NSN 2925-01-228-4437
NSN 6610-01-537-0816
NSN 6685-01-429-1279
NSN 5905-01-634-0595