五月婷婷六月丁香在线观看,久久国精产品一二区免费,成人在线观看1区2区3区,国产日韩欧美 ,国产精品福利一区二区_国产成人午夜性a一级毛片_国内一级特黄女人精品片_我想

Tempered glass/Reinforced glass is a safety glass. Tempered glass is actually a kind of prestressed glass. In order to increase the strength of the glass, chemical or physical methods are usually used to form compressive stress on the surface of the glass. When the glass is subjected to external force, the surface stress is first offset, thereby improving the bearing capacity and enhancing the resistance of the glass itself. Wind pressure, cold and heat, impact and so on.