Tempered glass is growing in popularity for use in homes and buildings due to its durability and safety features. But one question homeowners and contractors often ask is, can you cut tempered glass to a custom size after it has been tempered? We’re going to explore the truth around cutting tempered glass and discuss alternatives if you need a custom size.
What is Tempered Glass?
Before we dive into whether tempered glass can be cut, it’s important to understand what tempered glass is and how it differs from regular glass. Tempered glass goes through a heating process called tempering, which alters its internal molecular structure.
This tempering process strengthens the glass by 3-5 times compared to regular glass. So if broken, tempered glass shatters into small, relatively harmless pieces rather than large, dangerous shards.
Should You Attempt to Cut Tempered Glass?
In short – no. It is extremely dangerous to attempt cutting tempered glass once it has gone through the tempering process. The controlled internal stresses that give tempered glass its strength also cause it to violently shatter if you try to cut it.
What Happens If You Try to Cut It?
Rather than a clean cut, the tempered glass will burst into thousands of tiny pieces. These small fragments act like shards of glass shrapnel shooting in all directions.
| Risks | Consequences |
|---|---|
| Eye injuries | Potential blindness |
| Cuts and wounds | Infection |
As you can see, attempting to cut tempered glass can result in serious injuries. The uncontrolled shattering creates a major safety issue.
Why Can’t Tempered Glass be Cut?
The intense heating and rapid cooling of the tempering process gives the glass vastly improved tension and compression strength. But this same process leaves the glass in a precarious molecular state vulnerable to shattering.
Cutting and grinding creates vibration and pressure forces that can trigger the glass to instantly break apart. Even a single scribe or notch concentrates enough internal stress to cause rupturing.
Myths About Cutting Tempered Glass
You may come across claims that there are ways to cut tempered glass if you know the tricks. Common myths suggest:
- Annealing the glass first to remove temper
- Using specialized glass cutting tools
- Re-tempering the glass after cutting
However, these claims tend to originate from questionable sources. Legitimate glass experts agree tempered glass cannot be cut without shattering.
Alternatives to Cutting Tempered Glass
If you need a custom size or shape for your tempered glass application, there are a few options:
- Order the glass cut to size before tempering
- Carefully grind smooth edges after tempering
- Experimental laser cutting (extremely expensive)
Custom sizing the glass prior to tempering is the most reliable method. This allows the glass to be cut with standard tools. Then it undergoes strengthening through the tempering process.
Hopefully it is clear now that attempting to cut tempered glass results in shattered glass, not a clean cut. The durable, impact-resistant properties that make tempered glass suitable for homes and buildings also cause it to burst violently when cut.
Rather than risk devastating property damage and serious injuries from uncontrolled shattering, order custom tempered glass sizes or use standard glass if cutting is required.
