hss drill bits *Nice finishing, very good out-looking,and good quality * ... ,4341,9341,6541,M32 and M42 *ISO 9001 standard hss twist drill1.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 ... 31/6412.6-13.0 1/2 DIN338 hss straight twist drill bits with various surface finish