hss drill bits *Nice finishing, very good out-looking,and good quality *4241,4341,9341,6541,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 ... -12.5 31/6412.6-13.0 1/2 DIN338 hss straight twist drill bits with various surface finish