Used on f-22 raptor. countersunk cylindrical convex head style bolt, special (LK108) head of bolt is flat; washer is bonded to head per 5PTPKL20, no adhesive overflow on bottom
Used on RQ-4A. 2a thread class right-hand 1.500" thread length round w/wrench flats chamfered head style 12 thread quantity per inch drive bolt unc thread series