What's the difference between full tempered and half tempered glass
May 20, 2026
Tempered glass(fully tempered) is actually a type of prestressed glass. To enhance its strength, we usually use chemical or physical methods to create compressive stress on the glass surface. When the glass is subjected to external forces, it first counteracts the surface stress, which in turn improves its load-bearing capacity and tensile strength.
Tempered glass has two main advantages. First, its strength is several times higher than that of ordinary glass-its bending strength is 3 to 5 times that of ordinary glass, and its impact resistance is 5 to 10 times higher. While increasing strength, it also improves safety. Safety in use is the second key advantage of physically tempered glass. Its increased load-bearing capacity reduces its fragility, even if tempered glass breaks, it shatters into small, non-acute fragments, which greatly minimizes harm to the human body. Additionally, tempered glass' resistance to sudden temperature changes is 2 to 3 times better than ordinary glass. It can generally withstand temperature differences of more than 150°C, which is highly effective in preventing thermal breakage.
Heat-strengthened glass(half tempered), also known as thermally strengthened glass, is a type between ordinary flat glass and tempered glass. It inherits the high strength of tempered glass while avoiding the latter's drawbacks, such as poor flatness, easy self-explosion, and complete shattering once broken.
When heat-strengthened glass breaks, it cracks radially from the source of the crack, usually without tangential crack expansion, so it can remain intact and not collapse after breaking. In construction, heat-strengthened glass is suitable for curtain walls and external windows, it can also be made into heat-strengthened coated glass, and its image distortion is better than that of tempered glass.
However, it's important to note that heat-strengthened glass is not classified as safety glass. Because once it falls, it can still produce sharp fragments that may injure people, so it cannot be used for skylights or occasions where human impact is likely to occur. The surface compressive stress of heat-strengthened glass ranges from 24MPa to 69MPa, while that of tempered glass is greater than 69MPa. The production process of heat-strengthened glass is the same as that of tempered glass, with the only difference being the wind pressure at the quenching station. Its resistance to sudden temperature changes is also lower than that of tempered glass.
