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Tempered Glass vs Annealed Glass

Tempered Glass

It’s important to realize that different industries and circumstances require the use of different types of glass. Two varieties that are frequently needed are tempered and annealed. At Northstar Glass, we offer custom glass replacements for residents and business owners around the Toronto area. Keep reading to find out more about the differences between tempered and annealed glass and what you should use them for.

What is Tempered Glass?


Tempered glass (also sometimes referred to as toughened or reinforced glass) is a type of glass treated by heat, or sometimes chemicals, to increase its overall structural integrity. The glass is exposed to an incredible amount of heat (over 600 degrees Celsius) and then cooled via a process called quenching. This quick process (it lasts just seconds) involves the use of highly-pressurized air blasts streaming from nozzles arranged in varying directions. Because quenching cools the outer surface of the glass more quickly than the centre, the outer surface becomes compressed and the centre remains in a state of tension. This is what gives tempered glass its strength. What is Annealed Glass?


This type of glass is usually referred to as standard glass. Unlike tempered glass, it’s treated with heat and then very slowly cooled. It’s roughly four times weaker than tempered glass and is only used in situations where reinforcement isn’t required. The Difference between Tempered and Annealed Glass

Tempered glass is generally used when strength and safety are necessary. It’s ideal for skylights, car windows, around showers and bathtubs, in storefronts, and in microwave ovens. In the event that it does break, tempered glass significantly reduces the risk of injury. This is due to the fact that it’s designed to break into dull, tiny and relatively harmless pieces; unlike annealed glass that breaks into long pieces with incredibly sharp edges. Annealed glass is generally used for double and single pane windows and is found on old cabinets and countertops. Since it’s much weaker than tempered glass, it should never be used anywhere where security and safety are important. Tempered Glass Uses

Here are some of the specific areas where tempered glass is typically required: Sports arenas. Hockey glass needs to withstand incredible force on a regular basis. The same can be said for racquetball courts and other types of sports locations. Glass railings. Railings need to be solid. Tempered glass will keep them steady for a long time. Display cases. Safety meets clarity when you use tempered glass for a display case.

If you’re in the market for glass repair or installation in Toronto, give us a call at Northstar Glass. Our experts will ensure your job is done properly and on time. Visit us here for more information regarding our products and services.

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