flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 0.400" grip length complete top surface of nut head shall be powder blasted passivate nut surface treated
Used on c-17a aircraft. 3a thread class right-hand straight pan head style 0.875" grip length 24 thread quantity per inch pin-rivet threaded aluminum surface treated unjf thread series