3a thread class right-hand flush countersunk head style 0.620" grip length 28 thread quantity per inch 10490 double pounds per square inch shear strength unjf thread series
3a thread class right-hand 0.433" grip length 28 thread quantity per inch 10490 double pounds per square inch shear strength cadmium surface treated unjf thread series
2a thread class right-hand 0.285" thread length hexagon extended washer head style 32 thread quantity per inch tap drill hole in top of head 0.375 in. deep, 0.164-32 unc-2b thread size, 0.250 in. min. full thd depth passivate surface treated unf thread series