Smackdown: Tempered vs Standard Glass!

It’s my favorite time of year—Halloween season! I don’t know about everyone else, but I love horror movies and one of the staples of iconic horror is… broken glass. Whether it’s the killer smashing their way inside to slice up some unsuspecting coeds or taking advantage so the poorly-dressed heroine can get a makeshift knife, broken glass is one of horror’s favorite props.

Glass is made up of three key components: soda ash, lime, and sand. These are melted at high temperatures, shaped, and formed. Then, this pre-glass material is heated again and allowed to cool in a process called ‘annealing.’ Annealing allows internal stresses out while adding strength. The differences between standard and tempered glass all come down to the length of time they are allowed to cool.

Standard glass is made to cool more quickly, allowing companies to produce more glass in a shorter amount of time. Standard glass can also be reworked. For example, it can be cut down to size, have its edges smoothed, and be drilled for holes without breaking. However, the glass is far more fragile and breaks into large shards—allowing killers and coeds to get those big horror movie chunks perfect for slashing. 

Tempered aka ‘safety’ glass is allowed to cool more slowly. This makes it much stronger and also changes the way it breaks. Tempered glass shatters completely, leaving no shards in the existing frame and also into very small ‘pebbles’ that have a smaller chance of inflicting injury. The downside to tempered glass is that it cannot be reworked in any way—it cannot be cut or drilled after creation, leaving a cost margin for companies to think about. 

As a general rule, everyone should be careful around glass products, but more things are made with tempered glass than you think. You probably know the obvious ones—windshields, shower doors, phone screens, and glass-topped tables. All sliding patio doors are also required to be made with tempered glass. Did you know that windows over a certain size, in bathrooms or near swimming pools, and low to the ground are all required to be made with tempered glass by law? 

While lots of doors and windows are made with standard glass and therefore the perfect fodder for horror movies, there are plenty of places in your home that wouldn’t allow this spooky season’s masked psycho to slice-and-dice you.