There’s a lot of buzz and marketing around tempered glass quality and options and it’s hard to pick apart what is true, what is propaganda, and what is most relevant to determine if a particular tempered glass is high-quality or not.

We reached out to one of our sources in Shenzhen, owner of one of the biggest tempered glass manufacturers in the world, and we asked him to break down the most important aspects of tempered glass in order to help us separate truth from myth. Here’s what we found:

  • Temper Time

The amount of time the glass spends tempering will determine whether it is fragile or not. The longer the temper time, the more resistant the glass will be. You can test the quality using the drop metal ball test: 75cm height, 35g hollow ball drop test.

Temper time4-8 hours2-3 hours2 or fewer hours
Drop Metal Ball Test
  • Oleophobic Coating

This oil will determine the touch feeling and scratch resistance. A good quality tempered glass will pass the friction test, where the glass is put in a machine and bend over 3000 times, as well as the water drops angle testing.

Oleophobic Coatingcovered by DAKIN oil from Japan Or ChinaCovered by other Chinese brands oilCovered by no brand Oil

  • Thickness of the Glass

While the 0.26mm is the best on the market, the 33mm is the most popular one found in most brands. Only a few factories use the 0.4mm glass, and the thicker the glass, the easier it will be to shatter, since it’s a harder surface and it won’t bend in a U shape like thinner versions.

Thickness of the glass0.26mm/0.33mm/0.4mm0.33mm/0.4mm0.33mm/0.4mm

  • AB Adhesive, OCA Film

The quality of the adhesive will determine if the tempered glass can exhaust air bubbles when fitted on the screen automatically, as well as if there are any bubbles remaining after installation. Good quality glasses will pass tests under high or low temperatures by exhausting air automatically and without bubbles under extreme weather.

AB adhesive. OCA filmGlue on the importLocal Chinese branded adhesiveNo brand adhesive
  • Material of the Glass

Overall quality. Hardness, transparency, etc.

Material of the glassJapan Asahi, Nanbo glass in Chinaother brands in Chinaother brands in China
  • 2.5D

Transparent 2.5D Glass cannot fully cover the screen. Silk printed black edged 2.5D glass will cover the screen. 2.5D is a smaller angle edge grinding arc. All tiers of tempered glass have the 2.5D glass.

  • Glued 3D

The glued 3D glass is a machine that grinds a larger radius after the 2.5D glass is gummed on all sides and finally reaches an angle big enough to cover the entire screen, offering a 360° protection to the screen. Essentially, the 2.5D glass is a flat surface, while the 3D is a curved one.

Glued 3DYesYesNo
  • Etching 3D

Etching 3D is the process of etching the intermediate glass on a 0.7mm glass to achieve the whole 3D effect, which is the same as the technology used on producing original screen glass panel. Only the best quality tempered glasses will offer this feature.

Tempered Glass QualityBestCommon Cheap

Don’t Be Fooled By The Marketing!

Many sellers will use big words to advertise their tempered glass as the best one in the market, with the latest technology, etc. But here’s the truth: a tempered glass will only be as strong as the amount of time it’s tempered.

Glass tempered for 4hrs or more will be a lot stronger than the ones subjected to less time. An easy way of determining how long that glass was tempered, is simply bending it in a U shape. If the glass bends and does not break, it’s been tempered long enough. Otherwise, it will shatter before forming a U, the closer to shattering at “U” shape the longer its been tempered.

Another technique marketers use is to advertise their tempered glass as 4D or 5D. Don’t fall for that. There are only two types of tempered glass, 2.5D and 3D, as we explained previously.

What About Liquid Tempered Glass?

We all heard of it, and many stores offer this option. Liquid tempered glasses are made out of liquid glass, whose base is Silicon Dioxide (SiO2).   SiO2 is a chemical found in quartz, sand and even inside our human bodies. Believe it or not, humans need SiO2 to survive. It is also used in food manufacturing amongst other things too.

From a cost and marketing perspective, offering liquid tempered glass can be a great option for your store. It’s cheaper than buying individual tempered glasses, and it’s a cool, easy marketing technique to get customers to add after a screen repair.  Liquid Tempered glass coatings do not last forever and depending on the formula a good brand can last a few years, but most of what we see in the market place only last 2 to 3 months before it’s all rubbed off from normal everyday usage.

Overall, the liquid glass is able to keep bubbles away, and it creates an oleophobic coating on its own, thanks to the silicon dioxide. However, when facing an actual tempered glass, there’s no match. Tempered glass offers much more reliable protection from scratches and accidents for a longer period of time.

Our advice is to offer both types at your store, at different costs, but being fully transparent with customers when explaining the differences between the two.


  1. I agree, this is interesting and helpful and will help educate customers. Does sourcely sell the Best quality tempered glass then?


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