Taper Shank HSS Twist Drill Bit *4241,4341,9341,6541,M32 and M42 *ISO 9001 standard *plastic sleeve packing *we are factory Taper Shank HSS Twist Drill Bit 1.Material:4241,4341,9341,6541,M32 and M422.Fully ground,roll forged and edge forged twist drill3.Special tip and more sharpness4.Application:More than 5MM stainless steel, spring steel, special steel, hardness of HRC40 within the metal block, ...