SDS MAX Carbide Bits feature the SDS MAX drive system for fast bit changes and efficient power transfer from the Hammer to the bit. Bits over 9/16 inch (5/8 inch)feature the highest quality carbide and provide two extra carbide nibs resulting in four cutting edges. These four cutting edges increase the drilling speed by pulverizing more concrete. They also provide a rounder hole than two cutter bits. The flutes provide a fast deep means of clearing concrete dust from deep holes speeding up drill rates. Use only in SDS MAX drive Hammers. SDS MAX bits also available in metric sizes. One per package.