Types of Tempered Glass

There are many types of tempered glass, which are primarily classified based on various factors such as shape, manufacturing process, tempering level, surface quality, and functional/composite properties. The specific classifications are as follows:

I. Classification by Shape

Flat tempered glass: The most widely used type, featuring a flat surface. It is suitable for conventional applications such as doors, windows, curtain walls, interior partitions, and glass railings.
Curved tempered glass (bent tempered glass): Shaped using special molds during the tempering process, it can be fabricated into single-curved, double-curved, or glass with varying radii of curvature. It is suitable for applications requiring distinctive designs, such as arched doors and windows, curved curtain walls, observation elevators, and glass furniture.
II. Classification by Process

Physically Tempered Glass (Quenched and Tempered): Ordinary glass is heated to a temperature close to its softening point and then rapidly and uniformly cooled with high-pressure cold air, creating compressive stress on the glass surface and tensile stress within the glass. This is the most commonly used tempering method and is suitable for most architectural and automotive glass.
Chemically Tempered Glass: The chemical composition of the glass surface is altered through ion exchange (by immersing the glass in molten salt) to form a compressive stress layer. It is suitable for thinner glass (2–5 mm), such as smartphone screens and ultra-thin glass for high-end doors and windows, but is relatively more expensive.
III. Classification by Tempering Level (Stress Grade)

Fully Tempered Glass (Standard Tempered Glass): With surface stress ≥90 MPa, it offers high impact resistance and shatters into small, blunt-edged fragments. It is the mainstream choice for architectural doors and windows, curtain walls, and automotive glass.
Semi-tempered glass (thermally strengthened glass): Surface stress ranges from 24 to 69 MPa; its strength falls between that of ordinary glass and fully tempered glass. Upon breakage, the fragments are larger, and the surface flatness is better. It is commonly used as a substrate for laminated glass, artistic partitions, or furniture countertops, but is not suitable for high-risk applications.
Ultra-high-strength tempered glass: With surface stress exceeding 4 N/cm, it offers a higher degree of tempering and exceptional impact resistance, making it suitable for special applications with extremely high safety requirements.
IV. Classification by Appearance Quality (Flatness)

Premium Grade: Extremely high flatness and excellent optical properties; primarily used for automotive windshields.
Standard Grade: Meets conventional building and decorative standards; primarily used for architectural decoration, doors, windows, etc.
V. Classification by Function and Composite Structure

Single-Pane Tempered Glass: A single layer of tempered glass; the basic safety glass.
Laminated Tempered Glass: A single pane of tempered glass bonded with a PVB (polyvinyl butyral) interlayer or similar film; upon breakage, fragments adhere to the film, preventing shatter and providing higher safety. Commonly used for skylights, canopies, bulletproof glass, etc.
Laminated Tempered Glass: Composed of two or more layers of glass (e.g., tempered + laminated) bonded together, combining high strength with safety.
Colored/Coated Tempered Glass: Glass treated with coatings, colored glazes, or coloring on the surface, combining safety and decorative functions; commonly used in building curtain walls or interior decoration.