These titanium bits are 600 harder than standard bits giving them a much longer service life extensive drill range from 1 to 10 mm made of high quality hss high speed steel and titanium coated assembled in a sturdy steel case with handy seperators for organisation titanium for superior toughness the high durability of the titanium nitride layer gives the titanium drill its unsurpassed wear resistance the titanium drill provides approx 6x longer service life compared to conventional hss