Tempered glass is widely used where architectural glazing needs increased mechanical strength and a safer breakage pattern. A useful specification, however, must do more than state ‘tempered’. It should define the complete make-up, dimensions, fabrication, performance, appearance and governing standard.
1. Start with the application and risk
Identify where the glass will be installed, how it is supported and what happens if it breaks. A curtain wall panel, entrance door, balustrade infill and shower enclosure have different load, edge exposure and post-breakage considerations.
Confirm whether the location requires safety glazing, fall protection, overhead glazing, security, fire performance or another regulated function. Tempering may be only one part of the required solution; some locations need laminated glass to retain fragments after breakage.
2. Define substrate, thickness and heat treatment
State whether the substrate is clear, ultra-clear, tinted, coated, ceramic-fritted or another glass type. Give the nominal thickness and identify fully tempered glass rather than using the general phrase heat-treated glass.
Thickness should be selected by structural calculation and applicable code—not by panel size alone.
For China-based production, GB/T 15763.2-2025 is the current product standard for tempered safety glazing materials in buildings. Building safety-glazing locations should also be reviewed against GB 46030-2025 and the requirements of the destination market.
3. Put every fabrication detail on the drawing
Tempered glass cannot be cut, drilled or notched after heat treatment. The approved drawing should therefore show overall dimensions, edge finish, corner treatment, hole diameter and position, notches, cut-outs, logo or stamp position, coating surface and orientation.
- Use a clear datum for every hole and cut-out.
- Identify exposed edges and required polish.
- Show hardware interfaces and required clearances.
- State which face is viewed from the exterior or room side.
- Control drawing revisions before release.
4. Agree tolerances and visual acceptance
Dimensional tolerance, bow, roller wave, edge quality, optical distortion and anisotropy should be reviewed before production. Large heat-treated panels can show optical effects that are inherent to the tempering process. Agree the standard, inspection distance, lighting conditions and any project samples rather than relying on subjective phrases such as ‘perfect glass’.
Use our tolerances and quality guide to structure this discussion.
5. Confirm performance and documentation
Ask for the documents the project actually requires: product conformity, heat-treatment records, dimensional inspection, heat-soak testing where specified, coating data, calculations or third-party reports. Heat-soak testing is a separate requirement and should never be assumed from the word tempered.
6. Send a complete enquiry package
A quotation can be more accurate when it includes drawings, glass schedule, quantities, required delivery sequence, destination, packing method and standards. If the final make-up is still being developed, send the application and performance targets first.
Explore our tempered glass capabilities or discuss the specification with our glass team.