Heller HSS-Co Cobalt Twist Drills DIN 338 RN - Heller 21235 9, This 6mm HSS-Co cobalt twist drill from Heller is equipped to tackle the toughest drilling jobs in stainless steel and metal. It is made from a special HSS steel with a 5% cobalt content. Sold singly. Heller 21235 9 0990 HSS-Co Cobalt Twist Drill DIN 338 RN 6.0mm - Single
