Used on acft,c-133. 3a thread class right-hand 0.425" thread length dished hexagon head style 2.678" grip length 28 thread quantity per inch cadmium surface treated unjf thread series
2a thread class right-hand 0.750" thread length hexagon head style 8 thread quantity per inch grip portion 0.994 dia. x 0.310 long cadmium surface treated concentric hole unthreaded unc thread series
3a thread class right-hand 1.250" thread length flat chamfer head style 0.061" hole diameter 24 thread quantity per inch cadmium surface treated unrf thread series