| Tempered glass is safety glass and it will pop into a million pieces when broken. Heat treated glass is a heat treatment to make it stronger but it's not safety glass. Either might work but if it gets too hot they WILL break. What you need is Pyrex glass that is heat resistant ( like bakeware) and will not break with the heat. Pyrex glass in flat sheets is VERY VERY expensive especially if you need a custom size with holes or cutouts for hinges. |