Part 1 of Glass tempering basics series
Ever wondered why tempered glass is everywhere — from your car windows to skyscraper facades? It’s not just about looks; it’s about strength and safety. In this first part of our series, we’ll break down the basics of glass tempering in a way that’s easy to follow. By the end, you’ll know what makes tempered glass so tough and why heating technology is the real hero behind the process.
Glass tempering might sound complex, but understanding the essentials makes it much easier to grasp. In this first part, we’ll walk through the key concepts that form the foundation of the process.
What is glass tempering?
Tempering is all about making glass stronger and safer. It starts with heating float glass to over 610°C, then rapidly cooling it with air pressure. This quick change creates internal stresses: the surface compresses while the center stretches. The result? Glass that’s 3–5 times stronger than regular annealed glass.
Tempered vs. Heat-Strengthened glass
- Tempered Glass: Safety glass with surface compression above 90 MPa (or 120 MPa for thin glass). If it breaks, it shatters into small, harmless pieces.
- Heat-Strengthened Glass (HS): Lower stress levels (30–80 MPa). It doesn’t break into tiny pieces, making it ideal for applications where visibility matters. HS glass becomes safety glass only when laminated.
Heating technology basics
Heating is the heart of tempering. Glass absorbs heat through:
- Conduction: Heat transfer via contact, like rollers in the furnace.
- Radiation: Heat emitted from heaters to the glass surface.
- Convection: Air movement transferring heat — especially effective for coated glass.
Choosing the right heating technology ensures consistent quality, especially with modern coatings that reflect heat.
This is just the beginning! In the next Part 2 blog, we’ll dive deeper into convection technology. Stay tuned!
Interested in learning more? More tips, practical guidelines and easy-to-grasp theoretical information on our Tempering line Buyer’s Guide.