Precision ground metric drill bits made from M42 high speed steel bars with 8% cobalt achieving a hardness of some 63.5 - 65 Rockwell. The Cobalt allows the drill bits to hold their hardness at higher temperatures. Intended for use on alloy and hardened steels, cast iron, titanium and many other really tough, hard-to-drill, materials such as stainless steel. Perfect for home and production use. Available in a range of metric sizes. It is advisable to use coolant when appropriate.
Red Barn Man
12 June 2017
Worth the extra costThese are little short of fantastic. Wanted to drill a number of 10mm diameter holes in 8 and 10mm steel (using a battery electric drill) over 50 in total - all achieved with just one of these drill bits and a little oil. Edges a little blunter now but will still cut without having to pilot with a smaller drill first because of the split point design. I don't think I'll ever bother with ordinary HSS drills again!