Killing the Myth of "9H"

Xtyle Odeon Elephant Tempered Glass Explained To the Rest of Us

Why should you buy Xtyle Odeon tempered glass?

Smartphone have become such personal companion in our lives that we take them everywhere we go, increasing therefore risks of accidents. 45% of US smartphone owners have experienced at least once an incident during which their smartphone’s touchscreen got shattered. 8 times out of 10, this event took place within the first 12 months after purchase, and for fewer than 25% of these cases, in the first three months. Having your device’s touchscreen repaired is not covered by the phone maker’s warranty, is costly, especially if the service is performed with original spare parts in an authorized service center by the brand. So protecting your touchscreen with a tempered glass might be not only smart and safe, but also saving you a lot of money. Think of it as an insurance policy.

Forewords about tempered glass

Tempered glass, also known as “toughened glass” is an almost invisible, high performance material ideally suited to safely protect your touchscreen. Like your car windshield, it has much higher resistance to impacts than standard glass. To manufacture tempered glass, regular glass is first heated to 900°F = 480°C which is the point of stress-relief, aka annealing point.  Once cooled down, the glass is reheated to 1,150° F = 620°C and rapidly cooled with forced air drafts.

                  Tempered glass can only protects the surface they cover. It is typically NOT a solution to protect your smartphone against scratches or impacts on the 4 sides and on the back of your device. If you are looking for a solution to provide 360 degree protection against scratches and impacts, you should reconsider and purchase an impact case from X.O.

                  X.O. runs impact tests on its high-grade edge-to-edge tempered glass. We use only the highest grade of sheets of tempered glass from Japan.  Our edge-to-edge tempered glass is tested for front impact only. Lateral impacts, exercising a force from one edge of the glass toward its center, are not tested; we do not provide any explicit or implicit warranty for such impacts and tempered glass is not considered having any specific resistance quality against such lateral force. We test our tempered glass resistance to front impact by dropping vertically a metal ball weighting 110 grams = 3.8 ounces onto the surface of our product from a height of 120 cm = 3.9 feet, matching normal drop conditions for an adult, and this is what is considered normal usage. Dropping your smartphone from the top of a bridge, a floor of a building, the top of a stairway, etc does not constitute normal usage conditions for this product.

                  Resistance to scratches of a given material is technically tested by measuring its hardness.  Most of our competitors advertise loudly on their packaging that their products feature a “9” hardness (supposedly on the Mohs hardness scale from 1 to 10, 10= hardness of diamond, the hardest natural mineral found on earth).  Frederic Mohs, a German mineralogist, created this scale in early 19th century. It simply consists of applying force of one of the 10 defining materials against the tested material. If the force exercised leaves a trace of the defining material, it means the tested material is harder than the defining material. If the test results in leaving trace of the tested material it means it is of a lesser hardness than the defining material. But it is physically impossible that any tempered glass ever reaches the score of sapphire or corundum, the mineral that defines the 9 score on Mohs scale.  Besides, all tempered glasses for smartphones are made of a sandwich of different layers, the outer layer (the one that should be scratched for testing material hardness) protecting the tempered glass layer, being a plastic derivative used as an oleophobic coat. Plastics are not minerals, therefore cannot be measured on a mineral hardness scale.  This is how irrelevant and meaningless these “9” hardness scores are. Nevertheless, our tempered glass are engineered to be resistant to repetitive, normal and usual scratches due to rubbing daily against objects against our smartphones in our pockets, bags, whether they are keys, hair pins, brushes and other metal and plastic domestic objects we are surrounded by.  We call it “ZERO MHI” for Misleading Hardness Information. Rubbing your phone fitted with a tempered glass against abrasive or sharp tools, chemically active or corrosive substances do not constitute normal use.

                  Edge-to-edge design is an essential quality of a high end X.O tempered glass. To understand this aspect, you need to know that smartphone makers have been moving away from absolutely flat touchscreen since 2015. In order for a tempered glass to offer its impact resistance feature, there must be no micro air bubble or space between the glass and the touchscreen surface.  And flat tempered glass having no flexibility, they can only rest on absolutely flat surface.  But Apple, Samsung, Sony, Motorola, and LG started to design curved touchscreen.  Sometimes, the curvature is visible to the naked eye, like the Galaxy S6/7/8 Edge. But even a very slight curvature, invisible to the naked eye, is enough to make a flat tempered glass essentially useless. Sometimes, a large central estate of the touchscreen is flat and only the last few millimeters at the edges are curved, like on an iPhone 6.  Sometimes, the curvature of the touchscreen starts much closer to the center of the touchscreen, even if it is undetectable to the naked eye, like on Sony Xperia XZ models or Motorola Z models. A flat tempered glass would be able to protect only the central estate of your touchscreen, leaving the rest of the touchscreen unprotected, while an edge-to-edge tempered glass, following the exact curvature of your touchscreen, is able to cover all of it. Above and beyond design, edge-to-edge tempered glass is a much more complex product to manufacture than flat tempered glass and provides superior quality of protection by design.

References:

Manufacturing Process

Mohs scale of hardness

9H tempered glass hardness, really?  

Corning Glass, best US glass factory, does not feature any hardness on their product data sheets: 

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