Here’s why Corning Gorilla Glass is so tough
Corning, the company that made the glass for the Edison bulb back in 1879, is now widely known for making glass for smartphones. Their premier product, Gorilla Glass, is a chemically strengthened glass mostly used in cars, houses, buildings, and is dominating the smartphone market as the ‘standard’ of screen glass.
Back in 2008, Corning presented its first version of Gorilla Glass in New York at its annual investor’s meeting. It was a thin sheet of glass that could handle everyday use and abuse hence not scratching the glass surface. By the year 2010, there were approximately 200 million devices that used Gorilla Glass 1. Most notably the Nokia N8.
But even before all that happened, someone already saw the potential. Steve Jobs himself called up Corning back in 2007 to ask if they could create tough glass for a new Apple product. That product was the first iPhone. Jobs wanted to set the iPhone apart from other phones because, at the time, mobile devices mostly used plastic.
Fast forward to 2012, Corning announced its 2nd generation of Gorilla Glass; 20% thinner than the original. Then the year after Gorilla Glass 3 came out, which is 40% more scratch-resistant than Gorilla Glass 2. By the time of the publishing of this article, Gorilla Glass 6, which, according to Corning, can withstand slight falls and drops.
The process of making this chemically strengthened glass involves a process called Surface Finishing. Molten alkaline potassium salt at a temperature of 400°C covers the glass. The smaller sodium ions in the glass are removed and replaced by the more abundant potassium ions from the salt bath. This process is called ion-exchange.
This massive amount of potassium ions occupies more space in the molecular structure. When the glass cools, you end up with a deep layer with high compressive stress, which results in a sheet of glass with increased strength, rigidity, and crack resistance.
Gorilla Glass is undoubtedly impressive, but it has its limitations. The most common versions used nowadays are Gorilla Glass 5. According to Corning, it can only resist drops from shoulder height on a hard or rough surface. Any worse than that, then expect the glass to have scratches or even a full shatter. Meanwhile, Gorilla Glass 6 can withstand 15 consecutive drops from 1 meter and is twice as good as Gorilla Glass 5. However, still, it isn’t technically shatter-proof and scratch proof.
Even though your phone’s screen has Gorilla Glass protection, it doesn’t necessarily mean you’re entirely safe. If you want to keep your screen free of scratches and safer when dropped, better use a screen protector.