1PC HSS Step Drill Bit Set Titanium Stepped Down Drill Bits Hole Cutter Material: HSS steel; Surface treatment : Titanium plating Size: 3-12mm Automatically Deburrs Holes as you Drill. Two-flute Design Gives You Faster, Smoother Cutting 3 sided shanks prevent slippage when in chuck We ship it by epacket,usually it takes 7-15 business days