Core conclusion: For safety reasons, the fillet radius of tempered glass is usually no less than R5 (5 millimeters).
Main influencing factors
Glass thickness (t) : This is the most important factor. The thicker the glass is, the larger the radius of the fillet is usually required to achieve both safety and aesthetics. This is a positively correlated relationship.
Application scenarios and security standards
Furniture glass (tables, cabinets, partitions) : This is the most common usage scenario. The principle that "the radius should not be less than the thickness of the glass" is usually followed. For instance, for 6mm thick glass, the rounded corners are often made of R6 or R8. For 10mm thick glass, the rounded corners are often made of R10 or R12.
Architectural glass (doors, Windows, curtain walls) : It needs to comply with stricter building codes and has higher requirements for preventing injuries from human impacts. The rounded corners are usually larger.
Household appliance glass (oven doors, refrigerator shelves) : It is determined based on the internal structure design and safety standards of the product, and usually has clear design specifications.
Production process: The slotting and edge grinding equipment in the glass processing factory has fixed tool and grinding wheel sizes, which also determines that they can produce conventional fillet sizes efficiently and economically.
Why can't the rounded corners be too small?
Safety first - Prevent chipped corners: The corners of tempered glass are the areas where stress is most concentrated. If it is made into sharp right angles or even small sharp corners, it is extremely easy for the entire piece of glass to "self-explode" or "shatter the edges" due to minor bumps. A sufficiently large rounded corner can greatly disperse stress, enhance the impact resistance of the glass and prevent accidents.
Processing restrictions: Before tempering, the glass needs to undergo processing such as "cutting → slotting → edge grinding" first. If the fillet radius is too small (for example, R2 is required), the tools for slotting and grinding are difficult to operate, and it is easy to cause edge micro-cracks. These micro-cracks will expand at high temperatures during the tempering process, resulting in a decrease in the yield of finished products.
Safety in use: The rounded corners can prevent cuts to the human body, especially for furniture and frequently touched items, which is a basic safety requirement.
Summary and Suggestions
General rule: If you are not sure, choosing a fillet radius R that is no less than the thickness of the glass itself is a safe and aesthetically pleasing option (for example, R8 or R10 for 8mm glass).
Consult a professional: The best approach is to directly consult your glass processing factory or supplier. They possess the most accurate equipment processing capabilities and experience data, and can provide you with the most economical, safest and most suitable suggestions based on your specific glass thickness and application.
