What IS Tempered Glass?
Tempered glass is regular annealed glass that has been processed by a controlled thermal process to increase its strength in comparison to annealed (untempered) glass. The glass is heated in a special oven almost to a liquid state, and then cooled very quickly to create a hardened outside surface. Then the interior of the glass is cooled more slowly, to create a balance of internal stresses.
This internal stress causes the glass to be much stronger than annealed glass (tempered glass is generally 4-6x stronger than annealed glass), and creates the characteristic breaking pattern and a greater resistance to high heat temperatures. Tempered glass must be fabricated fully with all holes, edging, and shaping done prior to tempering because of the internal stress. However, any coating (silver, paint, etc.) must be done after tempering due to the incredibly high temperatures in the oven.
Tempered glass is more prone to breakage at the edge where the tensile stress is greatest. When tempered glass is broken, it crumbles into granular chunks, instead of jagged shards. These nuggets of glass are less likely to cause injury, so some people refer to it as “safety glass”. The greater the surface stress, the smaller the glass particles will be when broken.
Tempered glass is often used in glass shower enclosures, glass doors and tables, backsplashes, shower walls, stair railings, glass storefonts and other architectural applications. It is often recommended for “pass through” applications where the back of the glass is not fully supported, or where the glass may come in contact with extreme changes in temperature.
- Custom shower door glass
- Low-iron display case glass & mirror
- Glass for railing systems
- Storefront glass
- Commercial entry doors
Gardner’s Tempering Operation Talent
As a way to add to our value-added product offering of Dreamwalls Color Glass, Acid Etched Glass, heavy glass bath enclosures and more, we are glad to be tempering products for our customers. We are very excited to be able to offer tempering to our fabrication capabilities in addition to our water-jet cutting, edging, painting, and CNC fabrication. Keeping more of these processes in-house allows our customers to get product faster, with more control over the outcome; without the risks associated wit
h additional traveling and handling. We are fully certified in 4mm ,5mm, 6mm, 10mm, and 12mm thicknesses.
Derek Rhoades is in charge of tempering operations and was integral to the set up of the line from the beginning. He comes to Gardner from Lydall. Rhoades is a Wilkes County native who also served in the Navy for 6 years – stationed in Hawaii. He lives in Mulberry where he resides with his wife, a hairstylist, and their young son.