| Standard | Focus | Key Difference | | :--- | :--- | :--- | | | Shape deviation of bent glass | Specific to curved geometries; uses chord length references. | | ISO 11485-1/2 | Curved glass in building | International standard largely based on DIN principles, but with different tolerance classes. | | ASTM C1464 | Bent architectural glass | US standard; uses different measurement tools (dial gauges vs. contour templates). |
| Standard | Curvature type | Method | Typical tolerance | |----------|----------------|--------|-------------------| | DIN 52305 | Cylindrical | Chord height | ΔR ±5 mm, f_c 0.15–0.30 mm | | ISO 11450 | Spherical & cylindrical | Profile projector / 3D scan | Varies | | ECE R43 Annex 14 | Automotive glazing | Same as DIN 52305 | ΔR ±3 mm (strict) | | ASTM C1464 | Flatness of curved glass | Optical comparator | 0.5% of radius | din 52305