Our MX4™ 4-Cutter SDS MAX Rotary Hammer Drill Bits with solid head carbide deliver up to 5x longer life in concrete with rebar. Engineered with guards to provide maximum durability in hard aggregate and rebar. We designed our MX4™ 4-Cutter bits with sharp centering tips for exact spot drilling in concrete. The integrated 4-cutter design prevents lock-up in rebar, reducing downtime. Variable flutes remove dust faster reducing heat & delivering up to 15% more holes per battery charge. The wear mark indicator on each drill bit shows you when they no longer meet the ANSI requirement. These MILWAUKEE® MX4™ 4-Cutter Drill Bits are ideal for concrete with rebar and masonry applications. Choose from single bits, bulk packs, or drill bit kits in a variety of sizes. standard chisels