Is 9H Tempered Glass Good? (Here Are the Facts)

Home modern style aluminum rail and tempered glass

Have you seen the 9H label at the top of your device screen protector? 9H simply refers to the Moh scale of mineral hardness, invented by Friedrich Moh in 1812. I will clarify how the manufacturers come up with the scale and what it implies. But first, let me quickly answer what most consumers usually ask. 

Is 9H tempered glass good?

9H tempered glass has the highest hardness rating based on the Moh scale of mineral hardness. The higher the Moh scale, the more the tempered glass is going to protect your device. Besides, it provides up to 98% transparency despite having a high thickness. 

9H tempered glass is mostly used as device screen protectors. Its ability to effectively protect your screen is largely attributed to two qualities: hardness and thickness. To understand how strong a 9H tempered glass is, let me clarify the meaning of 9H on your screen protector. 

What is the Meaning of the 9H Label on Your Tempered Glass Screen Protector?

Friedrich Moh claimed that the hardness of minerals is classified into 10 levels – so his scale ranges from 1 to 10. Diamond at the top of the scale and glass around the 5th of the scale. The Moh scale is represented by a number with no “H” suffix. I will tell you what the “H” stands for as we go along. But first, have a look at the summary of the scale.

MineralsHardness (and common objects)
Gypsum2 ( Fingernail 2)
Calcite3 (Copper penny 3)
Fluorite4 ( Iron nail 4.5)
Apatite (glass falls here)5 (Glass 5.5)
Orthoclase feldspar6 ( Steel file 6.5)

The “H” suffix in the 9H refers to the hardness of a pencil (with a lead hardness). The hardness of the pencil ranges from 6B to 9H.  

During testing, the manufacturers scratch the surface of the screen protector starting with the 6B pencil ( with the softest lead hardness) to the 9H pencil ( with the toughest lead hardness). 

Mobile phone with broken screen
Mobile phone with broken screen

If the pencils fail to scratch the surface of the tempered glass screen protector until a 9H pencil is used, it means the tempered glass screen protector has a 9H level of hardness. 

How Hard is the 9H Tempered Glass?

One benefit of the 9H tempered glass is that it is very strong. When a protector claims that it is 9H, it has been proven to resist scratches from the hardest pencil.

The table above indicates that glasses fall at the Moh hardness of 5-6 so that knives, coins, and keys made of copper and iron with Moh of 3-5 cannot scratch them.

I know up to there, you may wonder why Corning Gorilla Screens with a Moh above 6 are usually scratched. Well, the main cause of screen scratches is sand which can be estimated to have a Moh of 6-7. 

But look, we are talking about a tempered protector with a Moh of 9. Meaning, no knives, keys, coins, or sand in your pocket can scratch it. 

What is the Thickness of a 9H Tempered Glass Screen Protector?

Apart from screen protector hardness, thickness also contributes to the protection it provides. Basically, the thicker the tempered glass screen protector, the more it will protect the screen of your device. 

The width of a 9H screen protector ranges from 0.2mm to 0.5mm. That is thick enough to protect your smartphone screen from low-level drop scratching. 

However, the thickness is not for the tempered glass used to make the protector alone. The tempered glass is covered with penetrative silicon coating on top to make it more resistant to scratching. 

Depending on the manufacturers, a tempered glass screen can have up to 3 additional layers including: 

  • Nanostructured coating
  • Anti-shatter film
  • Penetrable silicone coating, on top of the glass.

Here is the summary of how the lawyers are arranged: 

Though this level of thickness doesn’t make it as clear as most of the “D series”, they can allow up to 98% transparency. 

Does 9H Tempered Glass Screen Protector Stop Your Screen From Cracking?

With the level of hardness and thickness discussed above, a 9H tempered glass screen protector can protect your phone from cracking in some cases. This will depend on some factors such as, type of the phone, how it falls, and what it falls on. If it hits concrete or tile, for instance, there is a high possibility that your phone screen is going to crack. However, the extent to which it will crack will be reduced with the protector on. 

Besides, the screen protector does not protect the screen of your phone from damages that may occur on the sides or the corners. That said, your phone may land in a way that renders the protector useless when falling. 

How Durable is 9H Tempered Glass?

Getting 9H tempered glass for device protection has become the choice of most people partly because of its durability. With care, a 9H tempered glass screen protector will last indefinitely. If you don’t drop your phone more often, the 9H screen protector will outlast other components of your phone battery.

9H tempered glass has a special design that makes it thick, strong but still allows adequate light through. It is easy to install and long-lasting so that once installed, you should not worry about frequent replacement. 

The Bottomline

If you need a strong screen protector that will last you years, 9H tempered glass screen protectors are a great deal. They will protect your device screen from damages and allow very minimal or no scratches to the protector.