3a thread class right-hand 2.516" thread length double hexagon extended washer head style 9 thread quantity per inch cadmium surface treated unc thread series
3a thread class right-hand 0.797" thread length hexagon head style 0.065" hole diameter 20 thread quantity per inch cadmium surface treated unf thread series
Used on f-100-p-100. 3a thread class right-hand 0.620" thread length double hexagon w/hole head style 0.042" hole diameter 32 thread quantity per inch unjf thread series