Today, smartphones are getting more expensive, major mobile phone manufacturers are trying hard to increase the price level as much as possible. For most people, a smartphone is a “valuable” thing, people are more and more inseparable from mobile phones. The mobile phone screen is the weak point for mobile phone hardware. Consumers always consider getting a screen protector applied the first time they get their new phones, a screen protector is always a “personal guard” for a mobile phone screen. Smartphones are the most used digital product every day, as long as you are using your mobile phone, the screen might be scratched, so applying a screen protector seems an essential step for a mobile phone.
For the general public, tempered glass film is most hardest among all kinds of screen protectors if we are talking about scratch resistance, and the most important parameter measuring the quality of a tempered glass film is the hardness, from an intuitive experience, the harder a tempered glass film is, the better it is naturally able to protect the mobile phone display. Merchants always advertise their tempered glass film as “9H” to show they are premium product quality, we can always find the word “9H” in the most conspicuous position of the product description or carton, even more, some merchants use words such as “diamond”, “sapphire” to describe their tempered glass, so how hard a “9H” tempered is it? Is it really as hard as a “diamond”?
The “Secret” of 9H for a Tempered Glass Film
In fact, the word “H” in “9H” refers to the hardness of the graphite pencil, H means hardness, B=black (blackness), the higher value the “B”, the darker color and softer the pencil is, the higher the value “H”, the harder a pencil is, the lighter the color. Pencil hardness ranking order: 10B, 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, 10H. 10B indicates the softest ink and the blackest color, and 10H is the hardest graphite with the lightest color, this is the key.
But the 9H hardness is not the right parameter to judge the hardness of tempered glass, what people use to measure the hardness of an object is the Mohs hardness scale, not the hardness of a pencil.
What is Mohs Hardness Scale?
The hardness index is described by quoting the Mohs hardness scale proposed by the German mineralogist Frederic Mohs. Mohs hardness scale is a standard for the hardness of minerals, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The method of comparing hardness by observing which minerals can scratch others is of great antiquity. Substances with high hardness will leave marks on substances with low hardness. After comparing the results of various minerals in nature, he divided the mineral hardness into 10 levels. The minerals representing these 10 hardness grades are Talc 1 (the lowest hardness), Gypsum 2, and Calcite 3, Fluorite 4, Apatite 5, Orthoclase feldspar 6, Quartz 7, Topaz (topaz) 8, Corundum 9, Diamond 10.
The materials that come into contact in daily life such as nail hardness is about 2.5, copper coins are 3.5-4, steel is 5.5, special glass can be close to 7, quartz (the main component of sand) is 7, diamond is 10, the Mohs hardness of ordinary glass is between 5-5.5,
How Hard is a Tempered Glass Film?
Corning (Gorilla Glass), tempered glass specially used for iPhone and many other smartphone displays, is the leading company in the mobile phone tempered glass industry, has not stated the Mohs hardness scale for its own tempered glass products so far, even the latest Gorilla Glass Victus (Gorilla Glass 7), the other famous tempered glass manufacturer, Asahi Dragontrail Glass (AGC. Inc) has not disclosed the hardness level either.
China’s tempered glass suppliers such as CSG, Luoyang Glass, and Xuhong Opto-Electronics have no official data available to show the hardness of their glass. We can only use data from third-party, for example, the test data provided by Youtube channel JerryRigEverything shows that Mohs hardness of tempered glass is at least 5 (this is certainly true because the hardness of ordinary glass is also 5-5.5), according to the data from another mobile blog site Android Authority, the Mohs hardness of Gorilla Glass 5 is between 5-7 (no more than 7). We have reason to believe that the Mohs hardness of tempered glass film is between 5-7, more inclined to 6-7 (but no more than 7) through a large amount of data collection.
The Biggest Lie in Screen Protector Industry
So what is the 9H hardness advertised by the tempered film manufacturer? This is a complete lie! 9H is just a means of propaganda in the tempered film industry!
Then we are curious about how much the 9H hardness of the pencil refill is equivalent to the Mohs hardness? According to the data, the hardness of 9H, which is almost the hardest in pencil refills, is only equivalent to level 2 or 3 in Mohs’s hardness scale. What is the equivalent of level 2 – 3? The hardness of Mohs hardness scale level 2 is roughly the hardness of gypsum, while the hardness of 3 is equivalent to the hardness of calcite or copper, and the Mohs hardness is nonlinearly enhanced between each level, each increment of one in the scale does not indicate a proportional increase in hardness. Simply put, the difference between 3 and 7 is very large.
Therefore, when businesses advertise their own products as 9H, they actually made a joke to the public, 9H = Mohs hardness scale 2 or 3, which is a very low hardness value, indicating that their own products are actually low-quality products (thinking of this, if any business sees this article, shouldn’t you quietly erase your 9H from the brochure?). Of course, we believe you will no longer be fooled by the merchant’s 9H when purchasing the tempered glass film now.
Through the explanation of this article, you should be clear that the Mohs hardness of the current tempered glass film can usually reach 5-7, it is neither 9(9H) advertised by the merchants, nor 2-3 converted from the 9H pencil hardness. In the current market, there is no doubt a tempered glass can prevent general hard objects from scratching the tempered glass, so consumers do not have to worry about the hardness of the tempered glass you are purchasing. Anyway, the tempered glass film itself is a mobile phone accessory. It is a consumer product, its purpose is to protect the mobile phone screen from scratches and bumps from any hard objects, if your tempered glass film is scratched or damaged, then replace it directly, it is usually cheap.
Can the Tempered Glass Film be Scratch-Resistant?
There are actually a lot of articles on the Internet that discuss the hardness of tempered glass, such as the hardness of the Gorilla Glass used on the iPhone. The main feature of Corning’s Gorilla Glass is right that it is scratch-resistant and with good performance of drop protection, so what is the meaning of applying tempered glass film?
Gorilla Glass does have good scratch-resistant and drop-resistant. Gorilla Glass has also been undergone several generations, each time the product performance has been upgraded. But so far, the information we have obtained is that the Mohs hardness of Gorilla Glass still maintains no more than 7, and you have to know that scratch resistance is not scratch-proof. If the tempered glass of your mobile phone screen is Gorilla Glass, yes, it is “immune” to ordinary metal or sharp tools such as keys and even steel knives, but the mobile phone screen may still be scratched, why? One day, you suddenly find a scar on your mobile phone, don’t be surprised, because it is most probably it is not scraped by general metal, the culprit may be sand. The main component of sand is quartz. In our nature, sand is common and exists anywhere, the Mohs hardness of quartz is 7, it can cause trouble to the surface of the mobile phone screens with high probability. In addition, the mobile phone may be scratched when it is dropped on the concrete floor.
Anyway, scratch resistance is not the only reason to purchase a tempered glass film, it is explosion-proof, drop protection, and if you want a better touch experience, a mobile phone tempered glass film is also a good choice, otherwise, the tempered glass film is not a must.
What is the Difference between 9H and 9D?
While searching for the tempered glass film, except the words 9H, you might also find some words like 9D, 10D, 12D, etc., then does 9D right means 9H? if not, what is 9D?
9H is not 9D, anyway, both 9H and 9D are marketing words for merchants created, it’s no more than making their own products more mysterious and higher technical content to consumers, and we have explained the difference between 2.5D and 3D tempered glass film, or even 9D tempered films is in another article, the D refers to dimensions, 2.5d or 3D corresponding to a flat mobile display or tempered glass and curved mobile phone tempered glass, similar to 9H, 9D is the manufacturer’s trick, it can be said it doesn’t make sense, you may simply consider 9D as 3D, merchants just want to emphasize that their tempered film has a very good arc in edges, which can cover the display better than others.
What else to consider when choosing tempered glass film except for the hardness?
The hardness corresponding to the scratch resistance, a good tempered glass film should also have good coverage on screen (well, we know it is hard to judge before getting it), good manufacturing process, the back adhesive makes the tempered glass film more easily in pasting operation, the thickness of the tempered film should be moderate, too thick, the worse overall hand feeling; too thin, tempered glass film gets weak; in addition, glass material, touch experience (anti-fingerprint coating), the performance of explosion-proof and drop protection, as well as light transmittance, there are some special but optional features, such as blue light, anti-peek, etc, it’s up to you if you need them or not.