Naco Nano-Composite Blue Coating Increases Tool Life Up To 30% Compared To Traditional Hss Annular Cutters. Cuts Difficult Materials, Including Steel, Cast Iron, Heated And Stainless Steels. Naco Nano Coating Offers Extra Protection Against Tool Wear And High Heat. M2 High Speed Steel. Cuts Only Necessary Material For Fast, Efficient, Quality Hole Making. 3/4" Weldon Shank Fits Most Magnetic Drill Presses. Also Called Magnetic Drills Or Mag Drills. For Use With Magnetic Drill Press Only. Do Not Use With A Standard Hand Drill Or Drill Press. Comes With Pilot Pin. 3" Depth Of Cut