kwb Drill Bits & Parts Metal twist drill bit set 610504 - KWB 421103, The kwb 421103 HSS Metal Twist Drill Bit Set features a 3 mm diameter and a total length of 79 mm, compliant with DIN 1412 C standards. Ideal for machining applications, this steel drill bit efficiently penetrates metal and sheet materials. It offers precise performance in construction and DIY projects. kwb 421103 HSS Metal Twist Drill Bit set 3mm Hex chuck DIN 1412 C