Tile and glass drills — Cutting Tools Outlet Guides How to Drill Porcelain Tile Porcelain drilling needs controlled entry, cooling and a suitable tile bit. Why a Tile Drill Chips Porcelain Chipping comes from impact, excessive pressure, poor cooling, vibration or a worn tile bit. How to Choose a Porcelain Tile Drill Bit Size Tile bit size follows the anchor, fitting or pipe penetration, not the tool brand.