Simpson Strong-Tie offers a complete line of premium-quality drill bits, core bits and chisels to handle any drilling and demolition need. SDS-max shank bits have a chisel-shaped drill bit head which penetrates the material and directs concrete dust into the multi-flute spiral. The proprietary flute geometry reduces vibration and optimizes impact energy transfers from the rotary hammer into the drill bit tip which enhances drilling speed and durability and reduces noise, stress and vibration on the operator. All the features of the quad-head dual-cutter are designed to improve durability and drilling speed. The high-volume, double-helix design of the quad-head bit comes with the patented, high-performance, reinforced core flute to maximize energy transfer. 3/4 in. x 21 in. SDS-max® Shank Quad-Head Drill Bit (Pack of 20).