Diameter: 12.5mm The Faithfull Professional Pre Pack Metric HSS Jobber Drill Bits are designed to meet the requirements of the professional user, these pre-packed drills are manufactured from M2 grade steel and are fully ground to meet the standard of DIN 338 and feature a 135 non-slip split point. Suitable for use in: Alloy steels, carbon steels, cast iron, hardened alloy steels and stainless steels.