10pc high speed twist drill bits great for metal smiths, metal working & drilling Ideal for drilling ferrous metals, tough casting sand forgings, working hardened stainless steel and other hard steels and tough high tensile strength nonferrous metals like titanium These will not lose their hardness with excessive heat build up Each has a 1/16" shank; 0.42mm in diameter Size #77 Pack of 10 in a plastic tubeBrand new