Diablo DHS4BITCT High-Performance Hole Saw Pilot Bit, 1/4 in Shank, Carbide | Diablo's new, high-performance hole saws deliver faster cutting performance and increased productivity. Diablo's hole saw system and mandrel design simplify the attachment process for fast and efficient hole saw mounting. These radical new hole saws provide ultimate cutting length to bore deeper holes in a single pass, tool-free plug ejection and variable tooth design for faster cuts.