4021571 PIN LOCK SQ 5/16X2-1/2

Reliable HLZ Partial Thread Bolt, Steel, A Grade, Zinc, Thread Type: Coarse, Thread Size: 1/2-6, Thread Length: 3-1/4 in, Hex Size: 0.725 to 0.75 in W x 0.826 to 0.866 in H, 5-1/2 in OAL