Our newly sourced HSS individual ground drill bits are made from quality Swedish M2 grade steel. They have been heavily tested at Axminster in our Skill Centre and manufacturing department and are suitable for many materials up to and including hardened steels to HRC-30. Everyone has been so impressed they are now being used in manufacturing and on our engineering courses. These bits are ground from solid high speed steel bar and offer excellent chip clearance, rigidity and quality of cut. Perfect for home and production use they are available in a large range of metric and imperial sizes. Remember to use coolant when appropriate. Outside diameter tolerance of H8 within ISO 286. This gives a close running fit.