Spyder Hex8 arbor and pilot bit assembly - 3/8-in hex, 1/4-in TCT drill bit, 1/2-20 thread Spyder's Rapid Core Eject™ arbor removes cores without prying, cuts at an angle, and enlarges existing holes Tungsten carbide tipped (TCT) pilot bit drills cement block, brick and other masonry materials Spin on, spin off saw mounting 2-7/8-In drilling depth