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 nut end tapped 1/4-28 unf-1b 0.320 in. min deep cadmium surface treated unf nut thread thread series
2a nut thread thread class right-hand nut thread 0.812" stud thread thread length 1.625" overall length 14 nut thread thread quantity per inch body diameter: 0.425 in. min. to 0.457 in. max.; thread series designator: stud end-5hf or 5 csf/onf; spec data: condition- as formed or stress relieved unc nut thread thread series