Used on a-10 aircraft. 3a thread class right-hand 0.466" thread length double hexagon head style 1.313" grip length 20 thread quantity per inch bolt, double hexagon, shear alloy 718 "x" indicates 0.0156 oversize body diameter, for applications to 900 deg f. cadmium surface treated unjf thread series
3a thread class right-hand 0.594" thread length crowned hexagon head style 32 thread quantity per inch slotted shank cadmium surface treated unjf thread series