5 Pcs HSS Titanium Coated Step Drill Bits Set SAE Sizes Bits Shank 3/16" 1/4" 3/8" Automatically Deburrs Holes as you Drill. Two-flute Design Gives You Faster, Smoother Cutting. Titanium Nitride Coating for Cooler Running, can effectively extend the service life of the drill bi Suitable for carbon steel plate, sheet iron, insulation boards, wood NOT FOR stainless steel A great helper for Carpenter.