3a nut thread thread class right-hand nut thread 0.938" stud thread thread length 2.570" overall length 16 stud thread thread quantity per inch navy special project 1/4-28 unf class 1b thd min lg 0.320 in. located longitudinally in center of 3/8-24 thd end cadmium surface treated unc stud thread thread series
2a nut thread thread class right-hand nut thread 0.312" stud thread thread length 1.094" overall length 24 nut thread thread quantity per inch stud end thread 0.002 in. oversize uns stud thread thread series