IRWIN 3 8 in 12 Step Drill Bit Vanity with Marble Top For custom vent fabrication and For custom vent fabrication and repair 600 Product Height (in 12 hole sizes M35 grade cobalt HSS High heat and abrasion resistance Longest cutting edge life Single fluted cutting edge for greater control and rounder holes Ideal for drilling holes in thin materials such as mild steel Sub Brand NA Brand Model Compatibility Universal Number of Hole Sizes 12 Diameters of Holes Drilled 3 16 in to 7 8 in Step Size 1 16 in Shank Size 3 8 in Shank Type Hex Material Cobalt Set Individual Individual Package Quantity 1 Warranty None CA Residents: Prop 65 Warning(s) Yes