What Type of Glass Cannot Be Cut? | Tempered, Toughened, Laminated Glass Explained
Not all types of glass are the same. There are specific varieties that you can cut and others that you simply "cannot" touch once they are fabricated. Understanding these differences is essential for a successful Window Repair in Clarksville, TN or a large-scale commercial project. In this blog, we'll dive into:
- What type of glass cannot be cut?
- Why can't you cut it?
- And what your best options are if you need Glass Repair in Clarksville, TN for a broken tempered or laminated pane.
Understanding this will save you time, money, and prevent potential injury. So, let's dive in!
What Is Tempered Glass and Can You Cut It?
Tempered glass is a special type of safety glass that is 'treated' to increase its strength and durability.
It’s made by heating glass in a kiln to extremely high temperatures (about 1200°F / 650°C), and then it gets rapidly cooled using high-pressure air.
This heating and rapid cooling process causes internal stress within the glass, making it about 4-5 times stronger than regular glass.
Because of this, tempered glass cannot be cut. If you try to cut it, the glass would shatter into small harmless pieces.
So, if you need a specific size or shape of tempered glass, it must be cut to size before the glass is tempered.
Can Glass Be Cut After Tempering?
The answer is: no.
Because the glass is tempered with built-in stress, trying to use a glass cutter or any other cutter tool will not create a score line that can be snapped cleanly.
Instead, it will cause it to shatter immediately across the entire glass panel.
If you need a glass cut to a certain shape or size, it must be done before the glass is tempered.
⚠️ WARNING: Stop Before You Cut
As mentioned above, attempting to cut this glass will cause it to explode instantly, creating a dangerous mess.
Don't risk injury or wasted money. It is safer, faster, and often cheaper to order a new piece cut to your exact specifications.
Is There Any Way to Cut Tempered Glass?
Technically, the only way to modify tempered glass is to anneal it — meaning, heat it back to a high temperature and allow it to cool slowly, removing the built-up stress.
But this process weakens the glass, and it’s extremely difficult to do at home. You'll need industrial equipment.
For most people, the answer remains: you cannot cut tempered glass safely or easily.
If you need to cut tempered or cut toughened glass, it's better and safer to:
- Order new glass cut to size first, and then temper it.
- Or, use a different kind of glass that’s able to be cut.
Can Professionals Cut Tempered Glass?
No, even cut professionally, tempered glass cannot be cut once the tempering process is completed.
Professionals can order new glass, cut to size, and then temper it afterward. There is no way to cut existing tempered glass safely.
If a job requires a piece of glass of a precise size and needs to be tempered, glazing companies will custom-make it by:
- Cutting regular glass first.
- Shaping it exactly.
- Tempering it after the cutting is complete.
Never attempt cutting tempered glass at home — it will only result in broken glass, a dangerous mess, and wasted material.
What About Laminated Glass — Can It Be Cut?
Yes, you can cut laminated glass.
Laminated glass is made with two or more layers of glass panes bonded together with a plastic interlayer.
This gives laminated glass strength and keeps it from shattering when broken.
To cut laminated glass, professionals use a glass cutter to score the surface, then they separate the layers by heating and slicing the plastic interlayer carefully.
It’s possible to cut laminated glass, but it’s tricky, and not something you should attempt with basic tools at home.
Can Regular Glass (Annealed Glass) Be Cut at Home?
Yes! Regular glass — or annealed glass — can be cut at home using basic tools like a glass cutter.
Here’s the general process:
- Use a glass cutter to score a straight line on the glass surface.
- Apply gentle, even pressure to break along the score line.
- Smooth the glass edge using sandpaper or a grinding tool.
When glass is used for simple projects like picture frames or small windows, it’s often regular annealed glass because it’s easier to cut and shape.
Keep in mind that thick glass or larger glass panels can be harder to handle safely.
So, What Type of Glass Should You Choose If You Need to Cut It?
If you need glass that’s able to cut easily, you should select:
- Regular annealed glass — easiest to cut at home.
- Laminated glass — can be cut professionally, though it’s trickier.
Avoid choosing tempered glass if you plan to alter the size of the glass later. If you want safety and the ability to customize, laminated glass may be the better choice — it offers strength and safety while still allowing for some modification.
Always know the glass type before starting a project — it will save you from a lot of broken glass and frustration.
Need Custom Cut Glass in Clarksville? We Can Help!
At Allnite Glass, we help people in Clarksville and nearby areas with all their glass needs.
If you need custom-cut glass for your home or business, just give us a call.
We offer free consultations and free quotes, so you can get the right glass without any stress or surprises.
Bullet Point Summary: Key Takeaways
- Tempered glass cannot be cut after it has been tempered.
- Tempered glass will shatter into small pieces if you try to cut it.
- Tempered glass is a type of safety glass treated to increase its strength.
- Laminated glass can be cut, but it’s more difficult than cutting regular glass.
- Always cut the glass before it’s tempered if you need a custom size.
- Glass cannot be cut once it has gone through the tempering process.
- Use a glass cutter for regular glass or have professionals handle laminated glass.
- Choose the correct type of glass depending on whether you need to cut to size.
- Trying to cut tempered glass yourself is unsafe and will break the glass.
- Always verify the glass type before starting a DIY or professional project.
If you want to know more about custom glass, we have a blog covering all of it. We'll give you tips on how to choose the right type for your need, how you can DIY it, and how you can order it. Read our blog here: The Ultimate Guide to Custom Glass
FAQs
Q. What glass cannot be cut?
A. Tempered (or toughened) glass cannot be cut once it's been processed. The tempering process changes its internal structure so that trying to cut it will cause it to shatter instantly. Laminated and bullet-resistant glass are also difficult to cut with standard tools because of their layered construction.
Q. What glass doesn't cut?
A. If you're asking about glass that won't cut you, laminated glass is designed with safety in mind. When it breaks, the plastic interlayer holds the shards together, reducing sharp edges. Tempered glass also shatters into small, blunt pieces that are less likely to cause serious cuts.
Q. Can toughened glass be cut?
A. No, toughened (tempered) glass cannot be cut after it's been manufactured. Cutting it will cause it to break or shatter completely. If it needs to be shaped or drilled, that must happen before the tempering process.
Q. Why can't tempered glass be cut?
A. Tempered glass is heat-treated to increase strength. This process creates internal tension that makes the glass strong, but it also means that any attempt to cut or score it disrupts the balance — causing the whole piece to explode into tiny fragments for safety.
Q. What glass is not easy to break?
- Tempered glass is up to five times stronger than regular glass.
- Laminated glass is made of multiple layers and holds together when broken.
- Bullet-resistant glass is specially engineered with layers of polycarbonate and glass to resist high-impact forces.
All of these are far more resistant to breaking than standard float or annealed glass.
Q. Can you cut double glazed glass?
A. Cutting double glazed glass is possible but tricky. A double-glazed unit is made of two panes of glass sealed together with air or gas in between. To cut it, you'd need to disassemble the unit, cut the individual panes (if they're not tempered), and reseal it — which can compromise insulation and is usually not recommended outside of a professional setting.
