When we talk about screen protectors, we often use technical terms to describe specific product features — such as water contact angle, double tempered, or triple tempered glass. But do you really know what “double tempered” and “triple tempered” actually mean?
These terms are commonly used to indicate the strength grade of tempered glass. They describe how many times the glass has been reinforced, which directly affects its hardness, toughness, and overall safety. Understanding these levels not only helps users make smarter choices but also highlights the manufacturer’s engineering expertise.
Where the “Strength” Comes From?
The strength of tempered glass is created through internal stress reinforcement. There are two main processes: physical tempering and chemical strengthening.
During physical tempering, the glass is rapidly heated and cooled to form a compressive stress layer on its surface.
Chemical strengthening involves a sodium-potassium ion-exchange process that makes the molecular structure denser, improving impact resistance and scratch durability.
Screen Protector Ion Exchange Treatment
Process Difference Between Double and Triple Tempered Glass
The key difference between double and triple tempered glass lies in the number of strengthening treatments and the stress-stabilization stage.
Single Tempered: One round of heat tempering.
Double Tempered: Heat tempering followed by chemical ion exchange.
Triple Tempered: Heat tempering + ion exchange + stress-balancing or secondary strengthening for deeper, more uniform stress layers.
Screen Protector Tempered
As a representative of premium tempered glass, Mietubl’s Triple-Strength Series uses dual ion-exchange and stress-balancing technology to ensure even stress distribution, reducing breakage risk and improving long-term safety.
| Single Tempered | Double Tempered | Triple Tempered | |
| Process | Single heat tempering | Heat + ion exchange | Heat + ion exchange + stabilization |
| Hardness | About 9H | ≥9H, more stable | ≥9H, deeper compressive layer |
| Impact Resistance | Standard | 20~30% stronger | 40~50% stronger |
| Features | SEntry level, low cost | Great value, scratch resistant | Premium, anti-shatter and edge-proof/td> |
What to choose?
In daily use, double-tempered glass meets most users’ protection needs — offering strong resistance to scratches and drops at an excellent price-to-performance ratio.
Triple-tempered glass is designed for high-end devices, providing superior anti-explosion, anti-edge cracking, and stability performance. Its higher transparency and smoother touch deliver a near-original screen feel, ensuring both protection and comfort.
Mietubl’s Strengthening Solution
Mietubl operates independent strengthening production lines, using high-alumina silicate base glass and imported ion-exchange salts.
By precisely controlling temperature and process duration, every glass sheet achieves uniform stress depth. Each screen protector undergoes dual testing — stress verification and light transmittance inspection — guaranteeing consistent quality and durability.
