right-hand 16 thread quantity per inch stepped inner periphery beyond threads, first step 0.250 in.lg 5.250 in.dia second step 0.093 in.lg 5.812 in. dia, inner surface of first step to be square with pd of thread within 0.003 in. total indicator reading
3b thread class left-hand 16 thread quantity per inch navy special project tapped hole locking feature to be spaced 90.0 deg apart paint surface treated
