Simpson 1/2" x 21" 2-Cutter Head SDS-Max Drill Bit, Carbide MDMX05021Model No. MDMX05021 Shank Type. SDS max Shank Head Type. 2 Cutter Head Diameter (in.) 1 2 Drilling Depth. 15 1 2 Length (in.) 21 Pack Qty. 1 Simpson's carbide tipped drill bits are premium quality, professional grade tools manufactured in Germany to the highest industry standards for Simpson Strong Tie. They are designed to meet precise tolerance requirements and incorporate proprietary features that enhance durability and drilling speed, while