SawMaster Tile Contractor Series Core BitsTile Contractor Series Core Bits Standard The CB Contractor Series Core Bits are designed to complement hand held drills for countertop and wall tile drilling, common in plumbing installations. Each core bit features a central carbide drill bit to guide each coring for precise, professional results. Applications Ceramic Tile, Floor Tile, Marble, Medium Hard Natural Stone Standard These blades have fair life and are the economical choice for small jobs