Tempered glass cannot be cut, drilled, or modified after the tempering process without causing the entire piece to shatter. The internal stress pattern created during tempering—compression on the surfaces and tension in the center—makes any penetration into the glass surface destabilize the entire structure, releasing stored energy and causing it to break into small pieces. All cutting, drilling, notching, and edge finishing must be completed while the glass is in its annealed (non-tempered) state, before the tempering process begins. This limitation requires precise measurements and planning before ordering tempered glass products. If size adjustments are needed after tempering, the only option is to order new glass cut to the correct specifications in its annealed state, then have it tempered to the required safety standards.
