Last updated: 2026-11-05
Bottom line. "280°C thermal shock" describes the maximum sudden temperature differential the glass can survive — it does not mean the vessel can be used continuously at 280°C. The first is resistance to instantaneous hot-cold cycling; the second is a sustained working limit. Treating 280°C as a working temperature is the most common misuse of this class of ware.
All figures below come from our Glassware page, which states data based on ISO 3585. These are ISO 3585 standard values, not RichTech test results.
| Property | Value |
|---|---|
| Thermal shock (borosilicate 3.3) | 280 °C |
| Softening point | ~820 °C |
| Coefficient of expansion | (3.3±0.1)×10⁻⁶/K |
| Soda-lime · thermal shock | ~120 °C |
Breakage depends on load as well as temperature. Our Glassware page publishes the stress-strain curve and fracture points:
| Material | Fracture stress |
|---|---|
| Borosilicate 3.3 | ~180 MPa |
| Soda-lime | ~70 MPa |
| Elastic modulus E | 64–76 GPa (E ≈ 70 GPa) |
These are ISO 3585 standard values, not RichTech measurements.
No — a different concept. 280°C is the ceiling for a sudden differential (for example, taken from boiling water and cooled immediately). It does not imply continuous use at 280°C. For the sustained working temperature of a specific product, check that product's page or confirm with RichTech — there is no site-wide sustained-temperature figure, and we do not state one here.
Its coefficient is roughly 9.0×10⁻⁶/K, nearly three times that of borosilicate 3.3. Greater dimensional change produces higher internal stress during a sudden shift, which more readily exceeds fracture strength (standard values: soda-lime fractures at ~70 MPa, 3.3 at ~180 MPa).
Not recommended. Operating past the design boundary makes breakage risk uncontrollable — and breakage typically happens in service, not at goods-in inspection.