IRWIN 3 8 in 12 Step Drill Bit Flooring Samples tempered glass with solid brass 20 Amp Receptacle tempered glass with solid brass pivots and anodized aluminum profiles Applications to woody brush and vines should be in the spring to early summer when plants are in full leaf stage 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 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