Bergen US PRO 3pc HSS Cone Step Drill Set 4 -32mm Features: Fully Polished Can be used on various materials including metal, stainless steel, aluminium, copper, iron, nickel, steel etc. Supplied in a metal case Specification: Size 1: 4,6,8,10,12,14,16,18,20,22,24,26,28,30,32mm, Size 2: 4,6,8,10,12,14,16,18,20,22mm Size 3: 4,6,8,10,12mm HSS 4241 DIN 338