HSS COBALT STEP DRILL BIT SETBrand NEW This set replaces 50 individual drill bits. Two flute design gives you faster, smoother cutting. 3 sided (TRI FLAT) shank will not slip in your drill's chuck. Cobalt coated for smoother cooler cutting. SELF STARTING No need for a pilot hole. Cobalt coated to reduce friction and run cooler Large bit has 3 sided shank and small bits have hex shank to prevent slip in driver chuck Automatically deburrs holes as you drill Long Life True M2 high