3b thread class right-hand 2.1600" overall length 0.2495" bore diameter 24 thread quantity per inch four slots on face of hex 0.093 in. min 0.098 in. max wide 0.056 in. min 0.061 in. max deep, drilled holes through alternate corners of hex 0.046 in. dia, nas 516-1 grease fitting cadmium all external/exposed metal surfaces surface treated single row, concave rollers unjf thread series