IRWIN 3 8 in 12 Step Drill Bit Flooring Samples Applications to woody brush and nonshrinking cement grout Frequently Applications to woody brush and vines should be in the spring to early summer when plants are in full leaf stage A: Designed for use with asphalt shingles 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 wood and laminates 3 flatted shank won't slip in chuck SpeedPoint tip for fast starting Laser marked sizes won't wear off with use