Used on hemtt family (heavy expanded mobility tactical trucks). 2a thread class right-hand 0.750" thread length flat chamfer head style 11 thread quantity per inch unc thread series
3a thread class right-hand 0.170" thread length flat countersunk head style 32 thread quantity per inch navy special project cadmium screw surface treated unjc thread series
Used on coast guard hu25 aircraft constant speed motor 1650-01-074-2890. 3a thread class right-hand 0.400" thread length crowned hexagon head style 28 thread quantity per inch known as webbler stop screw unjf thread series