Irwin Rotary Masonry Drill Bit, Carbide Tip Rotary Masonry Drill Bit, Carbide Tip Features: Diamond ground tip with more aggressive cutting angles for increase drilling speed. Changed back angle from 10 º to 24 º. More aggressive 26.0 mm flute pitch. Tested other carbide grades, current grade performed the best. Optimized flute geometry for fast dust removal. Large carbide tip for increased life. For drilling masonry blocks and bricks. Slow spiral for quick and easy debris removal. Bits 7/16"" and larger have reduced shanks.