2a 2nd end thread class 18 2nd end thread quantity per inch two 0.062 in. dia holes in hex for lockwire rigid, short center wrenching facility uns 2nd end thread series
2a 2nd end thread class two lockwire holes .065 to .075 in. dia located .250 to .310 from center of hex rigid, short center wrenching facility unf 2nd end thread series