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 388 and feature a 135 degree non slip split point. Suitable for use in: Alloy steels, carbon steels, cast iron, hardened alloy steels, stainless steels.The FAIPP420PRO Professional Jobber Drill Bits have the following specifications: Diameter: 4.2mm. Pack quantity: 2.