Faithfull Metric HSS Drill Bits are quality roll forged flute twist drills with a black oxide coating manufactured from HSS in accordance with DIN338 standard Suitable for use in alloy steels carbon steels and hardened alloy steel A cutting lubricant is recommended Although designed for cutting metal they are also suitable for drilling holes in plastic timber chipboard and plywood Supplied in a robust plastic case that secures and protects the drills The contents can easily be viewed through the flip action transparent lid