Gorilla Glass is used in every smartphone and smartwatch these days. Any device without it is considered cheap which is because of the wide popularity of the Gorilla Glass.
The question here is how much the Gorilla Glass has improved over the years. They keep making a new version every two years and most of us still do not know the differences between different types of Gorilla Glasses.
Gorilla Glass 6 was released in 2018, the latest iteration of Gorilla Glass is supposed to be resistant to drops from a height of 1.6 meters. I am going to compare gorilla glass 1 and all other types of gorilla glasses with each other.
The Problem with Comparison:
Corning who is the manufacturer of Gorilla Glass does not really compare the latest variants of the Gorilla Glass with the previous versions after the Gorilla Glass 3. They are focussing on increasing the drop resistance in each generation and each year they would change the method of testing. I think this is just to confuse the consumers so they are not able to calculate how much is the newer version of Gorilla Glass better than the last version.
Why would Corning do that?
Well, when you can not get the desired results you promised to your suppliers and consumers, the best thing is to confuse them.
I mean just look at the official product information sheet fro Gorilla Glass 5 and 6 from Corning below.
The graph for the gorilla glass 6 on the right does not even specify the thickness of the Gorilla Glass being used. We can not tell anything from the graph of the gorilla glass 6 how much shatterproof it is compared to gorilla glass 5. Sure, it says it is resistant to 1.5 times more height but that is really vague.
They did an excellent job for Gorilla Glass 3. They compared it with the previous version Gorilla Glass 2 in every test and represented the results for both in the graphs. Let me show you an example below.
We can easily tell by looking at the graphs that the Gorilla Glass 2 can withstand load up to 7500 g and Gorilla Glass 3 up to 15000 g. It is so easy to understand the difference when the results are presented as real numbers and not fake assumptions like it can withstand drops from 1 height better than previous generations.
You need to be transparent Corning and give us facts in numbers and figures. We do not want your word or your fake lab tests. I am not being biased or anything. I spent two days studying Gorilla Glass so I could come up with real figures for my audience. But I did not get what I needed because of all the reasons I am explaining right now.
A Brief History:
I will compare all the Gorilla Glass to the best of my knowledge. But a brief history of different versions who are not familiar very much with Corning Gorilla Glass.
Gorilla Glass 1
Gorilla Glass 1 was first used in the first Apple iPhone in 2007. It was revolutionary at the time. No other smartphone manufacturer had thought of using Gorilla Glass back then. Most of the smartphones in that time were using either plastic or soda-lime glass.
By 2010, Gorilla Glass was installed on around 200 Million devices.
Gorilla Glass 2
Gorilla Glass 2 was introduced in 2012. By 24 October 2012, Gorilla Glass was being used on around 1 Billion devices. Gorilla Glass 2 was 20% thinner than Gorilla Glass 1 and had better resistance to damage comparatively.
Gorilla Glass 2 was 0.2 mm thinner than Gorilla Glass 1 and was better at resisting scratches.
Gorilla Glass 3
Gorilla Glass 3 was introduced in CES 2013. Gorilla Glass was focussed on being more scratch-resistant while maintaining the impact resistance properties of the previous generations.
This was their live demo in CES 2013
They introduced Native Damage Resistance (NDR) which would help prevent deeper scratches. According to Corning, this would reduce 40% of the scratches on your screen.
Gorilla Glass was also a bit thinner than Gorilla Glass 2 by 0.1 mm.
Fun Fact: Gorilla Glass 3 is still the best variant among Gorilla Glasses to prevent scratches.
Gorilla Glass 4
Gorilla Glass 4 was introduced in 2014. This version was focussed on increasing the impact or damage resistance because a lot of people were breaking their smartphones’ screens. This was their Gorilla Glass 4 introduction video.
Let me be clear, I read about the impact resistance load on the Gorilla Glass 4. It can handle a lot less damage than Gorilla Glass 3. So they did not make the glass stronger. More on this later.
Gorilla Glass 4 is the thinnest glass overall from Gorilla Glass family ranging from 0.4-1 mm.
Gorilla Glass 5
Gorilla Glass was introduced in 2016 and was first used in Samsung Note 7 (which exploded, RIP). This version was also focussed on being more resistant to drops. Corning said this Gorilla Glass 5 will not crack 80% of the time from a fall of 1 meter and can also withstand a few drops from 1.6 meter.
It was advertised that Gorilla Glass 5 is 1.8 times more damage resistant on rough surfaces than Gorilla Glass 4.
Gorilla Glass 6
Gorilla Glass 6 was introduced in 2018. It is supposed to survive 15 drops from 1-meter drops and is at least 2 times better than the Gorilla Glass 5. This is where they start lying. Nothing in their product sheet or real-life tests can prove that this is true. I think the first smartphone to use Gorilla Glass 6 was Oppo F9 Pro or OnePlus 6T.
In the product sheet, the graph represented Gorilla Glass 6 is 1.5 times better in drop height performance than Gorilla Glass 5 rather than 2 times advertised initially.
Comparison of all Variants:
There are a lot of terms involved that I would like to explain before moving on to the comparison.
Optical Transmission: Optical transmission represents what percentage of light is transmitted through the Gorilla Glass. Not 100% of the light is transmitted. Some of the light is absorbed by the medium. In our case, the medium is glass. If you pay close attention, you would notice the optical transmittance is getting worse in each generation instead of getting better.
Vickers Hardness: The Vickers hardness test method consists of indenting the test material with a diamond indenter, in the form of a right pyramid with a square base and an angle of 136 degrees between opposite faces subjected to a load of 1 to 100 kgf. The full load is normally applied for 10 to 15 seconds. The two diagonals of the indentation left in the surface of the material after removal of the load are measured using a microscope and their average calculated. The area of the sloping surface of the indentation is calculated. The Vickers hardness is the quotient obtained by dividing the kgf load by the square mm area of indentation.
Source: Gordon England
Compressive Stress Compatibility: As the name suggests, compressive stress compresses a material and shrinks it. When the compressive stress is increased, the material will become ductile (soft but flexible) instead of brittle (hard and easy to break). Compressive Stress is represented by two parameters, Pressure (Mpa) and Depth of Layer (µm). The higher the values of both parameters, the stronger will be the material i.e. Glass. The relation between Pressure (MPa) and Depth of Layer (µm) is given by the graph below.
You can make sense of this by assuming that for every 20µm increment, the pressure decreases by 100 MPa. In other words, they are inversely proportional meaning if Pressure increases, depth of layer decreases and vice versa.
Fracture Toughness: Fracture toughness is a quantitative way of expressing a material’s resistance to crack propagation. If a part of the glass has been fractured, the fracture would not break everything around it. Instead, the fractured area would not spread itself and hold the integrity of the structure. The higher the value for fracture toughness, the more resistant the fractured area will be to collapsing the whole structure.
Thickness: This is easy. The thickness of the glass. Corning can make a version of Gorilla Glass in different thicknesses. For example, Gorilla Glass is available from 0.4mm to 1.2mm. So any Smartphone manufacturer can choose the thickness they desire. Further, Corning will make Gorilla Glass of other thicknesses too for large orders.
I am going to make a table and compare all of the versions or variants of Gorilla Glass.
| Glass Types | Optical Transmission (Higher is Better) | Vickers Hardness (200g Load) kgf/mm ² (Higher is Better) | Compressve Stress Capability (Higher is Better) | Fracture Toughness (Higher is Better) | Thickness (Lower is Better) |
| Gorilla Glass 1 | ∼ 93% | 701 | 800 MPa, 100 µm | 0.7 | 0.7-2 mm |
| Gorilla Glass 2 | > 92% | 649 | 950 MPa, 50 µm | 0.68 | 0.5-2 mm |
| Gorilla Glass 3 | > 92.6% | 649 | 950 MPa, 50 µm | 0.66 | 0.4-2 mm |
| Gorilla Glass 4 | > 92.5% | 596 | 850 MPa, 50 µm | 0.67 | 0.4-1 mm |
| Gorilla Glass 5 | ≥ 90.5% | 638 | 850 MPa, 75 µm | 0.69 | 0.4-1.33 mm |
| Gorilla Glass 6 | 90.5% | 678 | 900 MPa, 80 µm | 0.7 | 0.4-1.2 mm |
So, the Optical transmission of Gorilla has been decreasing each generation. I don’t know why since the glass is thinner now.
Hardness test shows a lot of similarities between each Gorilla Glass generation. Surprised to see that the hardest glass was the Gorilla Glass 1.
Compressive Stress is the most interesting. It started from 800 MPa, 100 µm for Gorilla Glass 1 and the latest Gorilla Glass 6 have 900 MPa, 80 µm. These two are almost exactly the same compressive stresses. After Gorilla Glass 1, the compressive stress capability started decreasing until Gorilla Glass 4. This is another proof that they did not even increase compressive stress from Gorilla Glass 1 to 6.
Fracture Toughness is the most important factor. When the glass is broken or become fractured and if the fractured pieces are not able to hold their surrounding, the whole structure would collapse. Not having enough fracture toughness can also cause small pieces of glass damage someone’s skin or even eyes.
Scratch vs Drop Resistance:
So ever since the Corning released Gorilla Glass 3, they stopped working on scratch resistance and only worked on improving the drop resistance. The thing is if you increase the drop resistance, the scratch resistance decrease and if you increase the scratch resistance, the drop resistance will decrease.
So, it is really hard to keep the balance between scratch and drop resistance. But drop resistance is more important for Corning and Most People apparently.
There are two terms here. The hardness of the Glass improves the scratch resistance but reduces flexibility. Reduced flexibility means that the glass will be more fragile for drops.
The second scenario is to improve the overall strength of the Glass by increasing flexibility around the corners and making the cracks more ductile rather than brittle. This scenario would increase the drop resistance and reduce the scratch resistance.
So it is really hard for Glass Manufacturers to keep the balance between hardness (scratch resistant) and flexibility (drop resistance).
Gorilla Glass 3 is still the most scratch-resistant glass from Corning. After Gorilla Glass 3, they moved their focus to increase the drop resistance. By increasing the drop resistance, the scratch resistance in the following generations of Gorilla Glass got compromised.
This is what I meant for Gorilla Glass 4, the impact resistance is the same but they increased the flexibility to make the glass more resistant to drops. Being flexible means it can absorb more shocks but is also poor for scratch resistance.
Here is the real problem; if you have a glass with really good drop resistance but poor scratch resistance (like Gorilla Glass 6), you should use it without any screen protector because the Gorilla Glass on the phone is strong enough. But then if you use it without a screen protector, it would be full of scratches in a couple of months because of poor scratch resistance.
This is why almost everyone uses screen protectors these days. The real reason is, we want to protect our screens from scratches and also we do not trust the strength the Gorilla Glass.
Who wants to take a chance on that Gorilla Glass 6 will protect my phone from 15 (1 meter) drops?
Conclusion:
- The best Gorilla Glass version for drop protection is Gorilla Glass 6 and the best version for scratch resistance is Gorilla Glass 3.
- Harder glass is required for scratch resistance but harder glass is more likely to break.
- Flexible (softer) glass is better for drop resistance but it can be easily scratched.
- Corning keeps changing the way it tests the new Gorilla Glass to confuse us. This is why the comparison is hard.
- Not much has changed from Gorilla Glass 1 to Gorilla Glass 6.
Sources:
The product information sheet of all the Gorilla Glass is not available on the official website. Therefore, I would like to link all of them here for each Gorilla Glass Variant.
Gorilla Glass 1 Product Information Sheet
Gorilla Glass 2 Product Information Sheet
Gorilla Glass 3 Product Information Sheet
Gorilla Glass 4 Product Information Sheet
Gorilla Glass 5 Product Information Sheet
Gorilla Glass 6 Product Information Sheet
Have a look at the data and compare them yourself. I am sure you will also find a lot of discrepancies and inconsistencies.
