Matipedia

Compare / Thermally toughened glass vs Chemically strengthened glass

Thermally toughened glass vs Chemically strengthened glass

Europe EN 12150-1 · Glass

Thermally toughened glass

Fully tempered safety glass: fb,k 120 MPa; breaks into small blunt fragments.

Europe EN 12337-1 · Glass

Chemically strengthened glass

Ion-exchange strengthened glass: fb,k 150 MPa; thin compressive layer, breaks like float glass.

Mechanical

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Modulus of elasticity E—70 000MPa270 000MPa2same
Shear modulus G—29 166MPa229 166MPa2same
Poisson's ratio ν—0.220.22same
Characteristic bending strength fg,k / fb,k—120MPa3150MPa1+25 %
Knoop hardness HK—6GPa26GPa2same

Design values

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Modification factor for load duration kmodinstantaneous load · wind gust, 3 s1111same
medium-term load · snow on heated buildings, 5 days0.4910.491same
permanent load · 15 years0.3210.321same
Partial factor for the material γMannealed glass part, γM;A1.811.81same
surface prestress part, γM;v1.211.21same

Physical

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Density ρat +18 °C2 500kg/m³32 500kg/m³3same

Thermal

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Coefficient of thermal expansion α20–300 °C9×10⁻⁶ /K29×10⁻⁶ /K2same
Specific heat capacity cp—720J/(kg·K)2720J/(kg·K)2same
Softening temperature Tso—725°C1725°C1same
Resistance to temperature difference ΔT—40K140K1same
Thermal conductivity λ—1W/(m·K)11W/(m·K)1same

Optical

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Refractive index nvisible light, 589.3 nm1.511.51same
Emissivity εcorrected (for U-value calculation), uncoated0.83710.8371same

Electrical and magnetic

PropertyConditionThermally toughened glassChemically strengthened glassDifference
Electrical resistivity ρeat +25 °C · 1 000 Hz5 × 10⁷Ω·m15 × 10⁷Ω·m1same

Rows are matched by condition (thickness band, temperature, product form). A dash means the grade has no sourced value for that condition. Differences are Chemically strengthened glass relative to Thermally toughened glass; for ranges the lower bound is compared.