How to Cut Tempered Glass

Quck answer

Cutting tempered glass is a delicate process that requires special tools and techniques. Here are the steps to cut tempered glass safely:

1. Measure and mark: Use a tape measure to measure the desired dimensions of the glass and mark them with a permanent marker.

2. Protect yourself: Put on safety gloves and goggles to protect yourself from any potential accidents.

3. Score the glass: Use a glass cutter to score along the marked line. Apply even pressure and make a single, continuous score.

4. Apply pressure: Place a straight edge along the scored line and apply pressure on both sides of the line to break the glass. Ensure that the cut is clean and smooth.

5. Smooth the edges: Use a glass file or sandpaper to smooth the edges of the cut glass.

Remember, cutting tempered glass should be done by professionals or experienced individuals due to the risks involved.


To cut regular glass, you can use a glass cutter to score it and then snap it along the score line. The same method can be used for cutting glass mirrors. Glass tiles, which are made of regular glass, can be cut using a glass cutter or a tile saw with a glass cutting blade.

However, tempered glass is different. There is no way to cut it without compromising its tempered quality.


Regular glass can be cut by scoring and snapping it along the score line.
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Image © ebestpicks.com

What Is Tempered Glass?

Tempered glass is glass that has been cut to its final shape and size, heat treated in a 1,148-degree Fahrenheit oven, and then cooled rapidly using high-pressure procedures. This rapid cooling causes the outer surfaces of the glass to cool faster than the center, creating tension between the surface and center of the glass. This tension makes tempered glass about four times stronger than regular glass. As long as the structure of the glass panel remains intact, its strength will remain stable. However, any attempt to alter the panel after tempering can disrupt this tension balance and cause the glass to shatter.

When tempered glass shatters, it breaks into small, relatively harmless fragments. Therefore, building codes require tempered “safety” glass for architectural use in public places. Tempered glass is also commonly used in residential settings for shower doors, patio tables, skylights, and oven windows. Tempered glass panels are always cut and shaped before tempering, and professional services may be able to grind down the edge slightly. However, the size of a piece of tempered glass cannot be altered.


Tempered glass is used in situations where regular glass would be dangerous.
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Image © Migo Glass

Misleading Instructions

There are online instructions that claim to explain how to cut tempered glass. These instructions typically involve placing the glass panel in a kiln or craft oven capable of heating the glass to at least 900 degrees Fahrenheit, followed by a specific cooling process. Essentially, this process removes the temper and turns the glass back into regular glass. At that point, you can cut it, but it will no longer have the desirable properties of tempered glass. If the result of this complex procedure is just regular glass, why not start with regular glass in the first place?

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