3/16 x 1 Hex Insert Bit - 1/4 Hex Shank

3/16 x 1 Hex Insert Bit - 1/4 Hex Shank . A unique combination of alloys (nickel, vanadium and molybdenum) give these insert bits a Rockwell hardness of RC 59-62 without the brittleness. ITM TECH3 insert bits are the ultimate for the professional who demands and deserves only the best.