Which is the Hardest Tempered Glass?
Tempered glass is a staple in modern technology, from smartphone screens to car windows, valued for its strength and safety. But not all tempered glass is created equal—some types push the boundaries of durability further than others. In this article, we explore what makes tempered glass “hard,” how different types compare, and which stands out as the toughest in 2025.
What Makes Tempered Glass Hard?
Tempered glass is made by heating regular glass to over 600°C and then rapidly cooling it, creating compressive stress on the surface and tensile stress inside. This process makes it up to five times stronger than regular glass and causes it to shatter into small, blunt granules rather than sharp shards when broken. The “hardness” of tempered glass refers to its resistance to scratches, impacts, and bending, determined by factors like:
- Composition: Additives like alumina or magnesium can enhance strength.
- Thickness: Thicker glass is generally more durable but less flexible.
- Manufacturing Precision: Uniform cooling and minimal defects boost performance.
- Coatings: Some tempered glass has protective layers for added scratch resistance.
To determine the hardest tempered glass, we need to look at both material science and real-world performance, focusing on brands and technologies leading the industry.
Top Contenders for the Hardest Tempered Glass
Several companies dominate the tempered glass market, each with proprietary technologies. Below, we compare the leading options based on hardness, strength, and practical applications.
1. Gorilla Glass Victus 2 by Corning
Corning’s Gorilla Glass has been a household name in smartphone displays for years, and Gorilla Glass Victus 2 is its latest flagship. Released in 2022, it’s designed to withstand drops from up to 1 meter onto concrete and offers twice the scratch resistance of its predecessor, Gorilla Glass Victus.
- Hardness: Rated at 7-8 on the Mohs scale (comparable to quartz).
- Key Features: Enhanced aluminum oxide composition improves scratch and crack resistance. It’s optimized for both smartphones and larger devices like tablets.
- Applications: Found in premium smartphones like the Samsung Galaxy S24 series and iPhone 16 lineup.
- Why It Stands Out: Victus 2 balances drop protection with scratch resistance, making it ideal for daily use. Lab tests show it survives 80% of drops from 1 meter, compared to 60% for older Gorilla Glass versions.
2. Dragontrail X by AGC
AGC’s Dragontrail X is a strong competitor, particularly in markets where cost-effective durability is key. It’s an aluminosilicate glass designed for high impact resistance, often used in mid-range smartphones and wearables.
- Hardness: Approximately 7 on the Mohs scale.
- Key Features: Lightweight yet tough, with a focus on resisting micro-abrasions. It’s about 30% lighter than some competitors, making it ideal for wearables.
- Applications: Used in devices like Xiaomi and Oppo smartphones, as well as smartwatches.
- Why It Stands Out: Dragontrail X offers excellent value, delivering near-premium performance at a lower cost. Its impact resistance is comparable to Gorilla Glass but slightly less scratch-resistant.
3. Sapphire Glass
Sapphire glass, made from synthetic sapphire (aluminum oxide crystals), is often touted as the ultimate in hardness. It’s not technically tempered glass but is sometimes used in similar applications, like high-end watch faces and camera lenses.
- Hardness: 9 on the Mohs scale, just below diamond.
- Key Features: Exceptional scratch resistance but more brittle than aluminosilicate glass, making it prone to cracking under impact.
- Applications: Found in luxury watches (e.g., Rolex, Apple Watch Ultra) and some smartphone camera lenses.
- Why It Stands Out: Sapphire glass is unmatched for scratch resistance, but its brittleness limits its use in larger screens. It’s also significantly more expensive.
4. Ceramic Shield by Apple (Corning Collaboration)
Apple’s Ceramic Shield, developed with Corning, introduces nano-ceramic crystals into the glass matrix, blending the benefits of glass and ceramics. Introduced in 2020, it’s been refined for the iPhone 16 series.
- Hardness: Around 7-8 on the Mohs scale, with enhanced crack resistance.
- Key Features: Claims to offer 4x better drop performance than standard tempered glass. The ceramic infusion reduces flexing, improving structural integrity.
- Applications: Exclusive to Apple’s iPhone and iPad Pro lines.
- Why It Stands Out: Ceramic Shield excels in drop tests, surviving 90% of drops from 1.2 meters in lab conditions. However, its scratch resistance is similar to Gorilla Glass Victus 2.
Comparing Hardness and Performance
To determine the “hardest” tempered glass, we need to consider both scratch resistance (measured by the Mohs scale) and impact resistance (tested through drop and bend tests). Here’s a quick comparison:
| Glass Type | Mohs Hardness | Drop Resistance | Scratch Resistance | Cost |
|---|---|---|---|---|
| Gorilla Glass Victus 2 | 7-8 | High (1m on concrete) | Excellent | High |
| Dragontrail X | 7 | Moderate-High | Good | Medium |
| Sapphire Glass | 9 | Low-Moderate | Outstanding | Very High |
| Ceramic Shield | 7-8 | Very High (1.2m) | Excellent | High |
- Scratch Resistance: Sapphire glass wins for its near-diamond hardness, but it’s impractical for most applications due to cost and brittleness.
- Impact Resistance: Ceramic Shield leads, followed closely by Gorilla Glass Victus 2, thanks to their advanced compositions.
- Versatility: Gorilla Glass Victus 2 strikes the best balance, offering robust performance across both metrics at a reasonable cost.
Which is the Hardest?
If we define “hardest” strictly by scratch resistance, Sapphire Glass takes the crown with its 9 on the Mohs scale. However, for most practical applications—like smartphone screens—Gorilla Glass Victus 2 is the hardest and most well-rounded tempered glass available in 2025. Its combination of scratch resistance, drop protection, and widespread adoption in premium devices makes it the top choice for manufacturers and consumers alike.
Ceramic Shield is a close contender, especially for Apple users, but its exclusivity limits its reach. Dragontrail X is a solid budget option, while sapphire glass remains a niche luxury choice.
Factors to Consider When Choosing Tempered Glass
When selecting a device with tempered glass or a screen protector, keep these in mind:
- Use Case: If scratches are your main concern (e.g., for a watch), sapphire glass might be worth the cost. For smartphones, Gorilla Glass or Ceramic Shield offers better all-around protection.
- Budget: Dragontrail X provides excellent value for mid-range devices.
- Device Type: Larger screens need flexible, impact-resistant glass like Gorilla Glass or Ceramic Shield, while smaller surfaces can leverage sapphire’s hardness.
- Screen Protectors: Aftermarket tempered glass protectors can add an extra layer of protection, often using Gorilla Glass or similar technologies.
Conclusion
The hardest tempered glass depends on your definition of “hard.” For scratch resistance, sapphire glass is unbeatable, but for a practical blend of durability, impact resistance, and cost, Gorilla Glass Victus 2 stands out as the champion in 2025. Whether you’re choosing a new phone or a screen protector, understanding these differences ensures you get the best protection for your needs.