While tempered glass tables resist scratches better than some other forms of glass, they're not scratch proof. Tempered glass, which is more durable than standard glass, can still break, scratch or shatter, but it's generally less likely to do so.
When you make glass, you anneal or heat it, and cool it once again to make it stronger. The annealing process is what gives glass its final properties. Standard annealed glass, such as the type used for mirrors and framed photos, cools quickly for more efficient manufacturing. This type of glass ends up being fragile, breaking into sharp shards. Tempered glass is standard glass that goes through yet another heating process in a special tempering oven. You cool it under high pressure very quickly, making it four to seven times as strong as a standard annealed glass pane with the same dimensions. You also can't cut or change it once tempered, so you have to cut and shape it before tempering.
Tempered glass breaks into tiny chunks instead of large, spear-like shards. Since it is less likely to cause harm when it breaks, you often see tempered glass on indoor and outdoor tabletops, doors and side and rear vehicle windows. Tempered glass is a form of safety glass, thanks to its strength and its ability to break into tiny pieces when damaged. The one potential downside is that a harsh impact on its edges could also cause the entire glass piece to break, rather than a simple chip coming off the glass, as with a standard glass pane.
Glass that's perfectly tempered resists scratches even from sharp objects such as razor blades. Sometimes during the tempering process, tiny particles of glass that should have been removed first end up fusing onto the glass pane. While these are too small to see, they can cause scratches when cleaning the glass tabletop. or if another object, such as a plate, slides over it. Usually, the tabletop is free from such issues, but it's best to treat the tabletop as any other household glass, protecting it from items that may cause scratches. Placemats and coasters help reduce potential scratches.
Why Choose Tempered Glass
Besides its ability to resist scratches, tempered glass also holds more weight and is less likely to shatter under minor impacts such as a toddler smacking her hands on top of it. A tempered glass topper used to protect a wood side table is also less likely to break or chip if accidentally dropped at an angle onto a rug. If a tempered glass tabletop does break, the resulting glass pebbles are far less likely to cause serious injury than if a standard glass table broke into shards.