Soda-lime glass Soda-lime
Silica-soda-lime glass: about 72.6% SiO2, 13.9% Na2O and 8.4% CaO, with 3.9% MgO and 1.1% Al2O3 (typical sheet composition)
Soda-lime glass is the common window and container glass.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Density
2500 kg/m3
Working temperature
110 °C not toughened
Softening point
715 °C
Bending strength
165 MPa fully tempered
Optics
1.523
Recipe, share of the weight
- SiO2 72.6%Silica
- Na2O 13.9%Sodium oxide
- CaO 8.4%Calcium oxide
- MgO 3.9%Magnesium oxide
- Al2O3 1.1%Aluminium oxide
- cullet 20%Recycled glass
Best for
Windows and containers where low cost and wide availability matter more than thermal shock or alkali resistance
Weakest at
Resistance to sudden temperature changes (high thermal expansion) and to alkaline solutions (NGA: poor resistance to alkalis)
Risk at a glance
- People None found. Hazard data partly checked: PubChem's classes for the raw…
- If it fails High. Attack by alkaline solutions
- Corrosion Severe. Poor resistance to alkalis.
Quick facts: Soda-lime
| Property | Value | Basis |
|---|---|---|
| Density | 2.5 g/cm³ | 1 sourced value |
| Young's modulus | 72 GPa | 1 sourced value |
| Thermal conductivity | 0.94 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 9.5 ppm/K | 2 sourced values across conditions |
| Specific heat | 880 J/(kg·K) | 1 sourced value |
| Maximum service temperature | 110 to 150 °C | 2 sourced values across conditions |
What is the density of Soda-lime glass?
Soda-lime glass has a density of 2.5 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Soda-lime glass?
Soda-lime glass has a thermal conductivity of 0.94 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Soda-lime glass?
Soda-lime glass has a coefficient of thermal expansion of 9.5 ppm/K. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the Young's modulus of Soda-lime glass?
Soda-lime glass has a Young's modulus of 72 GPa. The source and test conditions are listed in the properties table on this page.
What is the maximum service temperature of Soda-lime glass?
Soda-lime glass has a maximum service temperature of 110 to 150 °C. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is Soda-lime glass used for?
Uses recorded in the sources include Window glazing (flat glass); Soda-lime glass spheres for valves, bearings and mixers.
Why it exists
Soda-lime glass is the most common glass. Soda and lime added to silica lower the melting temperature, which keeps production cheap. Wikipedia says it accounts for about 90% of manufactured glass. The trade-off is a high thermal expansion, so Continental Trade says the glass has low resistance to sudden temperature changes.
Where it's used
Windows
Wikipedia gives windowpanes as the main use of flat soda-lime glass, and says the float process makes window glass.
Containers
Wikipedia says container glass is used for beverages and food, where its durability is required for storage.
Valves and bearings
Kugelpompel sells soda-lime glass spheres for special bearings and valves, mixers, metering pumps and flow meters.
Recipe
Silica-soda-lime glass: about 72.6% SiO2, 13.9% Na2O and 8.4% CaO, with 3.9% MgO and 1.1% Al2O3 (typical sheet composition)
Soda-lime glass is an amorphous silica network modified by sodium and calcium oxides. Float glass is made from sand, soda ash, limestone, dolomite and salt cake, with about 20% recycled glass (cullet). Pilkington says making glass from cullet takes half the energy of making it from raw materials. The composition below is a typical sheet composition from Continental Trade. No producer's exact batch recipe is published.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Silica SiO2 | 72.6% | The main network former. It gives the glass its rigid, mostly silica framework. |
| Sodium oxide Na2O | 13.9% | Added as soda ash (sodium carbonate). It lowers the melting temperature of the silica. |
| Calcium oxide CaO | 8.4% | Added as limestone. It stabilises the glass network. |
| Magnesium oxide MgO | 3.9% | Comes in with the dolomite in the batch. |
| Aluminium oxide Al2O3 | 1.1% | Minor oxide in the typical sheet composition. |
| Recycled glass cullet | 20% | Broken glass put back into the batch as a melting aid. |
Weight shares are as printed in the sources.
What it can do
Density
2500 kg/m3
measured
Continental Trade gives 2500 kg/m3 at 18 °C. Pilkington gives the same figure.
Working temperature
110 °C not toughened
measured
Continental Trade gives a working limit of 110 °C for not-toughened glass and 150 °C for toughened glass.
Softening point
715 °C
measured
Pilkington gives 715 °C (ASTM C338) for float glass. The NGA paper gives 715 to 729 °C.
Bending strength
165 MPa fully tempered
measured
Pilkington's mean bending strength is 41 MPa for annealed glass, 83 MPa for heat-strengthened and 165 MPa for fully tempered glass.
Optics
1.523
measured
Pilkington gives 1.523 for the sodium D line.
How it compares
Soda-lime float glass has a linear thermal expansion of 8.3 x10^-6 /°C (Pilkington, 75 to 575 °F), and Wikipedia gives 9.5 ppm/K for the flat-glass column. Its working limits are 110 °C for not-toughened glass and 150 °C for toughened glass, with a softening point of 715 °C. Those limits and its annealing point of 548 °C set the practical ceiling for most uses. Its bending strength depends strongly on temper.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | Soda-lime | Borosilicate | Aluminosilicate |
|---|---|---|---|
| Thermal behavior and safety | |||
| Thermal conductivity | 0.937 W/(m·K)6 | 1.2 W/(m·K) | 0.0109 W/cm.K |
| specific heatPrinted as 0.21 Btu/lbm.F (0.88 kJ/kg.C). | 0.88 kJ/(kg·K) | 0.83 kJ/(kg·K) | 0.768 J/(g.K) |
| Physical and electrical | |||
| Density | 2500 kg/m31 | 2.23 g/cm³ | 2.38 g/cc |
| Knoop hardness | 470 kg/mm211 | 480 HK0.1/20 | no data |
| Mohs hardness | 5 Mohs12 | no data | no data |
| Other measurements | |||
| Young's modulus | 72 GPa2 | no data | 73.6 GPa |
| Modulus of rigidity (shear) | 30 GPa3 | no data | 30.1 GPa |
| poissons ratioPrinted as 0.22 in the Poisson's Ratio row. | 0.22 - | 0.2 dimensionless | 0.23 - |
| Linear thermal expansion coefficient | 8.3 x10^-6 /°C4 | 3.25 x10^-6 K^-1 | 31.7 x10^-7/C |
| Linear thermal expansion coefficient (flat glass) | 9.5 ppm/K5 | 3.25 x10^-6 K^-1 | 31.7 x10^-7/C |
| refractive index | 1.523 -7 | 1.471 nd (587.6 nm) | 1.51 - |
| Softening point (ASTM C338) | 715 °C8 | 815 °C | 971 °C |
| Annealing point (ASTM C336) | 548 °C9 | 560 °C | 722 °C |
| Strain point (ASTM C336) | 511 °C10 | no data | 669 °C |
| Modulus of rupture, annealed, mean | 41 MPa13 | 25 MPa | 800 MPa |
| Design stress, annealed (0.8% breakage probability) | 19 MPa14 | 25 MPa | 800 MPa |
| Modulus of rupture, heat-strengthened, meanPrinted as 12,000 psi (83 MPa). | 83 MPa | 25 MPa | 800 MPa |
| Modulus of rupture, fully tempered, meanPrinted as 24,000 psi (165 MPa). | 165 MPa | 25 MPa | 800 MPa |
| Maximum working temperature, not toughened | 110 °C15 | no data | no data |
| Maximum working temperature, toughened | 150 °C16 | no data | no data |
Why choose it, and why not
Good for
- Windows and container glass, where low cost and wide supply matter more than high-temperature or thermal-shock performance.
- Spheres for valves and bearings, where chemical inertness and a smooth surface are needed (Kugelpompel).
Watch out for
- The thermal expansion is high. Continental Trade says the glass has low resistance to sudden temperature changes.
- Bending strength depends strongly on temper: annealed glass has a design stress of 19 MPa against a mean of 41 MPa (Pilkington).
- Humidity can cut the failure strain of soda-lime-silicate glass (Ronchetto 2019, 80% RH at 50 °C for 28 days). Ageing of sheet glass in service is not covered by the sources read here.
Soda-lime glass is the low-cost default for windows and containers. The sources agree on density, expansion and the softening point, and they give clear working and thermal-shock limits. Its weak points are alkali resistance and thermal shock. No flight, radiation or vacuum result was found.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density | Printed as 2 500 kg/m3 in the Density (at 18 °C) row. Pilkington ATS-129 gives the same 2500 kg/m3 (156 lb/ft3). | temperature 18 °C | — |
| 2 | Young's modulus | Printed as 10.4 x 10^6 psi (72 GPa) in the Modulus of Elasticity (Young's) row. | basis float glass, Pilkington North America | — |
| 3 | Modulus of rigidity (shear) | Printed as 4.3 x 10^6 psi (30 GPa) in the Modulus of Rigidity (Shear) row. | basis float glass, Pilkington North America | — |
| 4 | Linear thermal expansion coefficient | Printed as 4.6 x 10-6 in/in.°F (8.3 x10-6 mm/mm.°C). The metric value is used here, unconverted. | temperature range 75 to 575 °F | — |
| 5 | Linear thermal expansion coefficient (flat glass) | Printed as 9.5 in the Coefficient of thermal expansion row, flat-glass column. Wikipedia gives 9 for container glass in the same row. The temperature range differs from the Pilkington value. | temperature range about 100 to 300 °C | — |
| 6 | Thermal conductivity | Printed as 6.5 Btu.in/hr.°F.ft2 (0.937 W.m/m2.°C). The metric value is used here. | temperature 75 °F | — |
| 7 | refractive index | Printed as 1.523 for the sodium D line. The NGA paper gives a mean of 1.5, which is a rounded figure. | wavelength sodium D line (printed as 0.5893 m) | — |
| 8 | Softening point (ASTM C338) | Printed as 1319 °F (715 °C). The NGA paper gives 715 to 729 °C. | standard ASTM C338 | — |
| 9 | Annealing point (ASTM C336) | Printed as 1018 °F (548 °C). The NGA paper gives 544 to 548 °C. | standard ASTM C336 | — |
| 10 | Strain point (ASTM C336) | Printed as 952 °F (511 °C). The NGA paper gives 504 to 511 °C. | standard ASTM C336 | — |
| 11 | Knoop hardness | Printed as ~470 - 605 kg/mm2 on the Hardness (Knoop's scale) line. It is a range, not a single measured value. | basis NGA range for typical soda-lime float glass | — |
| 12 | Mohs hardness | Printed as 5-6 in the Hardness (Mohs scale) row of the Pilkington bulletin. The Continental Trade sheet gives 5-6 as well. | basis Mohs scale, float glass (Pilkington) and sheet (Continental Trade) | — |
| 13 | Modulus of rupture, annealed, mean | Printed as 6,000 psi (41 MPa) in the Typical Mean MOR table. | glass kind annealedbasis mean MOR, 50% probability of breakage, 60 s load on weathered in-service glass | — |
| 14 | Design stress, annealed (0.8% breakage probability) | Printed as 2,800 psi (19 MPa) in the Typical Design Stress table. | glass kind annealedbasis design stress for 0.8% breakage probability | — |
| 15 | Maximum working temperature, not toughened | Printed as 110 °C on the Max. working temperature list, not-toughened line. | glass kind not toughened | — |
| 16 | Maximum working temperature, toughened | Printed as 150 °C on the Max. working temperature list, toughened line. | glass kind toughened | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Acids other than hydrofluoric acid | low | Excellent resistance to acids, other than hydrofluoric acid.1 |
| Alkaline solutions | severe | Poor resistance to alkalis.2 |
| Humid air under load, 80% relative humidity at 50 °C for 28 days | moderate | Humidity cut the failure strain of weathered soda-lime-silicate glass by 80%.3 |
| Humid air, 10% relative humidity at 50 °C for over 30 days | low | At low humidity the fatigue parameter did not change over 30 days.4 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Acids other than hydrofluoric acid | NGA rates the chemical resistance of typical float glass as excellent to acids other than HF. No rate or test duration is printed. | basis general chemical-resistance statement; no test conditions given |
| 2 | Alkaline solutions | NGA rates the chemical resistance of typical float glass as poor to alkalis. No rate, concentration or duration is printed in the paper. | basis general chemical-resistance statement; no test conditions given |
| 3 | Humid air under load, 80% relative humidity at 50 °C for 28 days | Ronchetto reports that failure strains decreased by 80% and that the fatigue parameter increased from 16 to 25 under these conditions. The specimens are commercial soda-lime-silicate glass, tested in the form the dissertation describes. | relative humidity 80%temperature 50 °Ctime 28 days |
| 4 | Humid air, 10% relative humidity at 50 °C for over 30 days | Ronchetto reports that weathering for over 30 days did not change the fatigue parameter, and that failure strain increased by about 10% over the first three days. | relative humidity 10%temperature 50 °Ctime over 30 days |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
No source opened in this run classes the finished glass. The only classes read are for its raw material, sodium carbonate (H319, eye irritation). No SDS for the finished glass was opened.
- Sharp edges
- Broken glass is sharp. Handle broken pieces with gloves and dispose of them in a sharps container.
- Soda ash powder
- PubChem's aggregated GHS for sodium carbonate is H319, causes serious eye irritation (Warning, 100% of reports). This describes the powder, not the finished glass.
- Heat
- Keep the glass below its working limits: 110 °C not toughened and 150 °C toughened (Continental Trade).
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Thermal shock of not-toughened glassmoderate severity | Temperature difference across the sheetContinental Trade gives a thermal shock limit of 50 °C for not-toughened soda-lime glass, and 118 °C for toughened glass. |
| Breakage of annealed glass under design loadmoderate severity | Load at the design stress for 0.8% breakage probabilityPilkington gives a mean bending strength of 41 MPa for annealed glass, and a design stress of 19 MPa for 0.8% breakage probability. |
| Humidity fatigue and ageing of commercial soda-lime-silicate glassmoderate severity | 80% relative humidity at 50 °C for 28 daysFailure strains decreased by 80% (Ronchetto 2019). |
| Attack by alkaline solutionshigh severity | Contact with alkaline solutionsNGA rates the chemical resistance of float glass as poor to alkalis, so the surface can be attacked. |
Handling and storage
- Keep not-toughened soda-lime glass below 110 °C and toughened glass below 150 °C (Continental Trade working limits).
- Keep temperature differences within 50 °C for not-toughened glass and 118 °C for toughened glass (Continental Trade thermal shock list).
- Keep the glass away from alkaline solutions. NGA rates acid resistance as excellent, except to hydrofluoric acid.
Supply and geography
How common the raw materials are and where they come from.
Soda ash (sodium carbonate)
USGS: world natural soda ash was about 19 million t in 2025 (estimated) and total world soda ash about 71 million t (2025e). China produced about 38 million t, mostly synthetic. Glass took 45% of US soda ash use in 2025.
- Top producers (2025)
- United States, Turkey, China
- Recycling
- USGS: no soda ash was recycled by producers, but glass container producers use cullet, which reduces soda ash consumption.
- Substitutes
- USGS: caustic soda can replace soda ash in certain uses, particularly pulp and paper, water treatment and some chemical sectors.
Soda ash, United States import sources
USGS: import sources for soda ash, 2021 to 2024, as printed.
- Top producers (2024)
- Turkey 89%, Canada 3%, Mexico 3%, Other 5%
- Recycling
- USGS: as above.
Silica sand (glassmaking sand)
USGS: US industrial sand and gravel sold or used was about 120 million t in 2025 (estimated). About 81% went to hydraulic-fracturing sand and 7% to glassmaking sand. Reserves are listed as large.
- Top producers (2025)
- China, United States, Netherlands
- Recycling
- USGS: about 33% of glass containers are recycled, so cullet is a significant proportion of reused silica.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: soda-lime-glass
spore_version: 0.2
family: glass-and-composites
name: Soda-lime glass
abbreviation: Soda-lime
role: window and container glass
category: glasses-optics
type: borosilicate
summary: |
Soda-lime glass is the common window and container glass. It is silica with sodium and calcium oxides added so that it melts at a lower temperature. Continental Trade's properties sheet gives a density of 2500 kg/m3 at 18 °C and Pilkington's float-glass bulletin gives a linear thermal expansion of 8.3 x10^-6 /°C. Pilkington gives an annealing point of 548 °C and a softening point of 715 °C. Wikipedia says soda-lime glass accounts for about 90% of manufactured glass. Its high thermal expansion means it tolerates sudden temperature changes poorly, so Continental Trade sets working limits of 110 °C for not-toughened glass and 150 °C for toughened glass. See the property list for the values and conditions.
best_for: Windows and containers where low cost and wide availability matter more than thermal shock or alkali resistance
weakest_at: 'Resistance to sudden temperature changes (high thermal expansion) and to alkaline solutions (NGA: poor resistance to alkalis)'
identity:
formula: 'Silica-soda-lime glass: about 72.6% SiO2, 13.9% Na2O and 8.4% CaO, with 3.9% MgO and 1.1% Al2O3 (typical sheet composition)'
source: continental-trade-sheet
where: Composition list, Soda-lime glass properties (Continental Trade)
tags:
environments: []
stresses: []
applications:
- structures
- mechanisms
properties:
- benchmark: density
value: 2500
unit: kg/m3
scope: material
conditions:
temperature: 18 °C
method: Printed as 2 500 kg/m3 in the Density (at 18 °C) row. Pilkington ATS-129 gives the same 2500 kg/m3 (156 lb/ft3).
status: ground
source: continental-trade-sheet
where: Properties list, Density row
- benchmark: elastic_modulus
label: Young's modulus
value: 72
unit: GPa
scope: material
conditions:
basis: float glass, Pilkington North America
method: Printed as 10.4 x 10^6 psi (72 GPa) in the Modulus of Elasticity (Young's) row.
status: ground
source: pilkington-ats129
where: Mechanical properties, Modulus of Elasticity (Young's) row
- benchmark: shear_modulus
label: Modulus of rigidity (shear)
value: 30
unit: GPa
scope: material
conditions:
basis: float glass, Pilkington North America
method: Printed as 4.3 x 10^6 psi (30 GPa) in the Modulus of Rigidity (Shear) row.
status: ground
source: pilkington-ats129
where: Mechanical properties, Modulus of Rigidity (Shear) row
- benchmark: poissons_ratio
value: 0.22
unit: '-'
scope: material
conditions:
basis: float glass, Pilkington North America
method: Printed as 0.22 in the Poisson's Ratio row.
status: ground
source: pilkington-ats129
where: Mechanical properties, Poisson's Ratio row
- benchmark: cte
label: Linear thermal expansion coefficient
value: 8.3
unit: x10^-6 /°C
scope: material
conditions:
temperature_range: 75 to 575 °F
method: Printed as 4.6 x 10-6 in/in.°F (8.3 x10-6 mm/mm.°C). The metric value is used here, unconverted.
status: ground
source: pilkington-ats129
where: Properties list, Coefficient of Linear Expansion row
- benchmark: cte
label: Linear thermal expansion coefficient (flat glass)
value: 9.5
unit: ppm/K
scope: material
conditions:
temperature_range: about 100 to 300 °C
method: Printed as 9.5 in the Coefficient of thermal expansion row, flat-glass column. Wikipedia gives 9 for container glass in the same row. The temperature range differs from the Pilkington value.
status: ground
source: wikipedia-soda-lime
where: Typical compositions and properties table, Coefficient of thermal expansion row, flat glass column
- benchmark: thermal_conductivity
value: 0.937
unit: W/(m·K)
scope: material
conditions:
temperature: 75 °F
method: Printed as 6.5 Btu.in/hr.°F.ft2 (0.937 W.m/m2.°C). The metric value is used here.
status: ground
source: pilkington-ats129
where: Properties list, Thermal Conductivity at 75 °F row
- benchmark: specific_heat
value: 0.88
unit: kJ/(kg·K)
scope: material
conditions:
temperature: 75 °F
method: Printed as 0.21 Btu/lbm.F (0.88 kJ/kg.C).
status: ground
source: pilkington-ats129
where: Properties list, Specific Heat at 75 °F row
- benchmark: refractive_index
value: 1.523
unit: '-'
scope: material
conditions:
wavelength: sodium D line (printed as 0.5893 m)
method: Printed as 1.523 for the sodium D line. The NGA paper gives a mean of 1.5, which is a rounded figure.
status: ground
source: pilkington-ats129
where: Index of Refraction, sodium D line row
- benchmark: softening_point
label: Softening point (ASTM C338)
value: 715
unit: °C
scope: material
conditions:
standard: ASTM C338
method: Printed as 1319 °F (715 °C). The NGA paper gives 715 to 729 °C.
status: ground
source: pilkington-ats129
where: Softening Point (ASTM C338) row
- benchmark: annealing_point
label: Annealing point (ASTM C336)
value: 548
unit: °C
scope: material
conditions:
standard: ASTM C336
method: Printed as 1018 °F (548 °C). The NGA paper gives 544 to 548 °C.
status: ground
source: pilkington-ats129
where: Annealing Point (ASTM C336) row
- benchmark: strain_point
label: Strain point (ASTM C336)
value: 511
unit: °C
scope: material
conditions:
standard: ASTM C336
method: Printed as 952 °F (511 °C). The NGA paper gives 504 to 511 °C.
status: ground
source: pilkington-ats129
where: Strain Point (ASTM C336) row
- benchmark: knoop_hardness
label: Knoop hardness
value: 470
value_high: 605
unit: kg/mm2
scope: material
conditions:
basis: NGA range for typical soda-lime float glass
method: Printed as ~470 - 605 kg/mm2 on the Hardness (Knoop's scale) line. It is a range, not a single measured value.
status: ground
source: nga-fm05
where: Hardness (Knoop's Scale) line, page 2
- benchmark: hardness_mohs
label: Mohs hardness
value: 5
value_high: 6
unit: Mohs
scope: material
conditions:
basis: Mohs scale, float glass (Pilkington) and sheet (Continental Trade)
method: Printed as 5-6 in the Hardness (Mohs scale) row of the Pilkington bulletin. The Continental Trade sheet gives 5-6 as well.
status: ground
source: pilkington-ats129
where: Properties list, Hardness (Mohs scale) row
- benchmark: flexural_strength
label: Modulus of rupture, annealed, mean
value: 41
unit: MPa
scope: material
conditions:
glass_kind: annealed
basis: mean MOR, 50% probability of breakage, 60 s load on weathered in-service glass
method: Printed as 6,000 psi (41 MPa) in the Typical Mean MOR table.
status: ground
source: pilkington-ats129
where: Mechanical properties, Typical Mean MOR table, Annealed row
- benchmark: flexural_strength
label: Design stress, annealed (0.8% breakage probability)
value: 19
unit: MPa
scope: material
conditions:
glass_kind: annealed
basis: design stress for 0.8% breakage probability
method: Printed as 2,800 psi (19 MPa) in the Typical Design Stress table.
status: ground
source: pilkington-ats129
where: Mechanical properties, Typical Design Stress table, Annealed row
- benchmark: flexural_strength
label: Modulus of rupture, heat-strengthened, mean
value: 83
unit: MPa
scope: material
conditions:
glass_kind: heat-strengthened
basis: mean MOR, 50% probability of breakage
method: Printed as 12,000 psi (83 MPa).
status: ground
source: pilkington-ats129
where: Typical Mean MOR table, Heat-Strengthened row
- benchmark: flexural_strength
label: Modulus of rupture, fully tempered, mean
value: 165
unit: MPa
scope: material
conditions:
glass_kind: fully tempered
basis: mean MOR, 50% probability of breakage
method: Printed as 24,000 psi (165 MPa).
status: ground
source: pilkington-ats129
where: Typical Mean MOR table, Fully Tempered row
- benchmark: max_service_temp
label: Maximum working temperature, not toughened
value: 110
unit: °C
scope: material
conditions:
glass_kind: not toughened
method: Printed as 110 °C on the Max. working temperature list, not-toughened line.
status: ground
source: continental-trade-sheet
where: Max. working temperature list, not toughened line
- benchmark: max_service_temp
label: Maximum working temperature, toughened
value: 150
unit: °C
scope: material
conditions:
glass_kind: toughened
method: Printed as 150 °C on the Max. working temperature list, toughened line.
status: ground
source: continental-trade-sheet
where: Max. working temperature list, toughened line
corrosion:
- environment: Acids other than hydrofluoric acid
headline: Excellent resistance to acids, other than hydrofluoric acid.
effect: NGA rates the chemical resistance of typical float glass as excellent to acids other than HF. No rate or test duration is printed.
rating: low
conditions:
basis: general chemical-resistance statement; no test conditions given
source: nga-fm05
where: Properties list, Chemical Resistance line, page 3
- environment: Alkaline solutions
headline: Poor resistance to alkalis.
effect: NGA rates the chemical resistance of typical float glass as poor to alkalis. No rate, concentration or duration is printed in the paper.
rating: severe
conditions:
basis: general chemical-resistance statement; no test conditions given
source: nga-fm05
where: Properties list, Chemical Resistance line, page 3
- environment: Humid air under load, 80% relative humidity at 50 °C for 28 days
headline: Humidity cut the failure strain of weathered soda-lime-silicate glass by 80%.
effect: Ronchetto reports that failure strains decreased by 80% and that the fatigue parameter increased from 16 to 25 under these conditions. The specimens are commercial soda-lime-silicate glass, tested in the form the dissertation describes.
rating: moderate
conditions:
relative_humidity: 80%
temperature: 50 °C
time: 28 days
source: ronchetto-2019
where: Abstract and results, fatigue and weathering tests
- environment: Humid air, 10% relative humidity at 50 °C for over 30 days
headline: At low humidity the fatigue parameter did not change over 30 days.
effect: Ronchetto reports that weathering for over 30 days did not change the fatigue parameter, and that failure strain increased by about 10% over the first three days.
rating: low
conditions:
relative_humidity: 10%
temperature: 50 °C
time: over 30 days
source: ronchetto-2019
where: Abstract and results, weathering at 10% RH
risks:
hazards:
- text: 'PubChem''s aggregated GHS for sodium carbonate, the raw material soda ash, is H319: causes serious eye irritation (Warning, 100% of reports). These classes describe the powder, not the finished glass.'
ghs:
- H319
source: pubchem-sodium-carbonate
where: Safety and Hazards, GHS Classification (CID 10340)
failure_risks:
- mode: Thermal shock of not-toughened glass
trigger: Temperature difference across the sheet
consequence: Continental Trade gives a thermal shock limit of 50 °C for not-toughened soda-lime glass, and 118 °C for toughened glass.
severity: moderate
source: continental-trade-sheet
where: Thermal shock list, not toughened line
- mode: Breakage of annealed glass under design load
trigger: Load at the design stress for 0.8% breakage probability
consequence: Pilkington gives a mean bending strength of 41 MPa for annealed glass, and a design stress of 19 MPa for 0.8% breakage probability.
severity: moderate
source: pilkington-ats129
where: Typical Design Stress table, Annealed row
- mode: Humidity fatigue and ageing of commercial soda-lime-silicate glass
trigger: 80% relative humidity at 50 °C for 28 days
consequence: Failure strains decreased by 80% (Ronchetto 2019).
severity: moderate
source: ronchetto-2019
where: Abstract and results, fatigue and weathering tests
- mode: Attack by alkaline solutions
trigger: Contact with alkaline solutions
consequence: NGA rates the chemical resistance of float glass as poor to alkalis, so the surface can be attacked.
severity: high
source: nga-fm05
where: Properties list, Chemical Resistance line
side_effects: []
handling:
- text: Keep not-toughened soda-lime glass below 110 °C and toughened glass below 150 °C (Continental Trade working limits).
source: continental-trade-sheet
where: Max. working temperature list
- text: Keep temperature differences within 50 °C for not-toughened glass and 118 °C for toughened glass (Continental Trade thermal shock list).
source: continental-trade-sheet
where: Thermal shock list
- text: Keep the glass away from alkaline solutions. NGA rates acid resistance as excellent, except to hydrofluoric acid.
source: nga-fm05
where: Properties list, Chemical Resistance line
mitigations: []
uses:
- application: structures
device: Window glazing (flat glass)
example: Wikipedia says soda-lime glass is used for windowpanes, and that the float process makes window glass.
source: wikipedia-soda-lime
where: Lead and Applications section
- application: mechanisms
device: Soda-lime glass spheres for valves, bearings and mixers
example: Kugelpompel lists special bearings and valves, mixers, low-cost control valves, metering pumps and flow meters as fields of application for its soda-lime glass spheres.
source: kugelpompel-soda-lime
where: Field of application
supply:
- subject: Soda ash (sodium carbonate)
abundance: 'USGS: world natural soda ash was about 19 million t in 2025 (estimated) and total world soda ash about 71 million t (2025e). China produced about 38 million t, mostly synthetic. Glass took 45% of US soda ash use in 2025.'
producers:
- country: United States
production: 12,000 thousand t, natural (2025e)
year: 2025
- country: Turkey
production: 6,000 thousand t, natural (2025e)
year: 2025
- country: China
production: about 38 million t, mostly synthetic (2025e)
year: 2025
critical_lists: []
recycling: 'USGS: no soda ash was recycled by producers, but glass container producers use cullet, which reduces soda ash consumption.'
substitutes:
- 'USGS: caustic soda can replace soda ash in certain uses, particularly pulp and paper, water treatment and some chemical sectors.'
source: usgs-soda-ash
where: Domestic Production and Use; Salient Statistics; World Mine Production and Reserves table (2025e); Recycling; Substitutes
- subject: Soda ash, United States import sources
abundance: 'USGS: import sources for soda ash, 2021 to 2024, as printed.'
producers:
- country: Turkey
share_percent: 89
year: 2024
basis: import sources 2021-24, as printed
- country: Canada
share_percent: 3
year: 2024
basis: import sources 2021-24, as printed
- country: Mexico
share_percent: 3
year: 2024
basis: import sources 2021-24, as printed
- country: Other
share_percent: 5
year: 2024
basis: import sources 2021-24, as printed
critical_lists: []
recycling: 'USGS: as above.'
substitutes: []
source: usgs-soda-ash
where: Import Sources (2021-24)
- subject: Silica sand (glassmaking sand)
abundance: 'USGS: US industrial sand and gravel sold or used was about 120 million t in 2025 (estimated). About 81% went to hydraulic-fracturing sand and 7% to glassmaking sand. Reserves are listed as large.'
producers:
- country: China
production: 92,000 thousand t (2025)
year: 2025
- country: United States
production: 120,000 thousand t, sold or used (2025e)
year: 2025
- country: Netherlands
production: 68,000 thousand t (2025)
year: 2025
critical_lists: []
recycling: 'USGS: about 33% of glass containers are recycled, so cullet is a significant proportion of reused silica.'
substitutes: []
source: usgs-industrial-sand
where: Domestic Production and Use; World Mine Production and Reserves table (2025 column); Recycling
documents:
- title: Soda-lime glass properties (Continental Trade information sheet)
type: datasheet
url: https://www.continentaltrade.com.pl/en/download/WhfvdEYg1jSqsBXM5x9dRJnJfIPvp1gO/soda-lime-glass-properties.pdf
- title: ATS-129 Properties of soda-lime silica float glass (Pilkington North America, 04/2025)
type: datasheet
url: https://www.pilkington.com/-/media/pilkington/site-content/usa/window-manufacturers/technical-bulletins/ats-129---properties-of-soda-lime-silica-float-glass.pdf
year: 2025
- title: FM05-12 (2023) Physical and Mechanical Properties of Typical Soda Lime Float Glass (National Glass Association)
type: report
url: https://www.glass.org/sites/default/files/2023-07/FM05-12_2023_Physical_Mechanical_Properties_Typical_Soda_Lime_Float_Glass.pdf
year: 2023
- title: 'Mineral Commodity Summaries 2026: Soda ash (USGS)'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-soda-ash.pdf
year: 2026
- title: 'Mineral Commodity Summaries 2026: Sand and gravel (industrial) (USGS)'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-sand-industrial.pdf
year: 2026
- title: Sodium carbonate, PubChem CID 10340
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/10340
- title: Data sheet Soda lime glass V1.01 (Kugelpompel, glass spheres)
type: datasheet
url: https://www.kugelpompel.at/img/cms/Datenbl%C3%A4tter%20Glas/Data%20sheet%20Soda-lime%20glass%20V1-01.pdf
year: 2020
- title: Soda-lime glass (Wikipedia)
type: report
url: https://en.wikipedia.org/wiki/Soda%E2%80%93lime_glass
- title: The effects of fatigue and weathering on the failure behavior of commercial soda-lime-silicate glass (Missouri S&T, Ronchetto 2019)
type: report
url: https://scholarsmine.mst.edu/doctoral_dissertations/2845
year: 2019
gaps:
- 'Property names not in spores/property-canon.yaml: softening_point, annealing_point, strain_point, knoop_hardness and hardness_mohs are used as snake_case names. The canon file needs them added before import.'
- 'Thermal stress coefficient (0.62 MPa/°C, Pilkington and Continental Trade) is not used: it has no canonical name.'
- Continental Trade thermal shock values (50 °C not toughened, 118 °C toughened) are used in failure_risks and handling only, because no canonical name fits.
- 'Container glass values: the Wikipedia table''s container column is not used for composition or expansion, because its columns were matched from a flattened table. Container-glass CTE is recorded only as Wikipedia''s 9 ppm/K in this note.'
- No glass-specific safety data sheet was read. The hazard entry uses PubChem's classes for sodium carbonate, the raw material, not for the finished glass.
- No open paper on soda-lime leaching or weathering could be read in this run. The Engineering and Technology Journal article URL returned 404 and the Venice repository returned 403.
- Dielectric constant, loss tangent and volume resistivity values were not found for soda-lime glass. NGA gives electrical resistivity only as High.
- No radiation, vacuum or space test of soda-lime cover glass was found. NASA TN D-7245 (1973) tests ceria-doped Micro-Sheet against undoped glass but gives no composition, so it is not used.
- Critical-mineral status of soda ash and industrial sand was not checked in this run.
- Ronchetto 2019 figures were read from the fetched dissertation landing page. The full-text PDF link returned an HTML page in this run, not a PDF.
- Kugelpompel data are for soda-lime glass spheres, not sheet or container glass. The sheet is used only for applications.
- Continental Trade prints Poisson's ratio as 0,23 with a decimal comma, which verify-values could not match, so that row was removed. Pilkington's 0.22 is kept. The sheet's 0,23 is a second reading for a future check.
- Wikipedia gives a flat-glass CTE of 9.5 ppm/K for about 100 to 300 °C, and Pilkington gives 8.3 x10^-6 /°C for 75 to 575 °F. The temperature ranges differ, so both are kept.
sources:
continental-trade-sheet:
title: Soda-lime glass properties (information sheet)
id: Continental Trade Sp. z o.o., Soda-lime glass properties
url: https://www.continentaltrade.com.pl/en/download/WhfvdEYg1jSqsBXM5x9dRJnJfIPvp1gO/soda-lime-glass-properties.pdf
kind: datasheet
license: supplier information sheet, cited not reproduced
pilkington-ats129:
title: ATS-129 Properties of soda-lime silica float glass
id: Pilkington North America, technical bulletin ATS-129 (04/2025)
url: https://www.pilkington.com/-/media/pilkington/site-content/usa/window-manufacturers/technical-bulletins/ats-129---properties-of-soda-lime-silica-float-glass.pdf
kind: datasheet
year: 2025
license: manufacturer document, cited not reproduced
nga-fm05:
title: FM05-12 (2023) Physical and Mechanical Properties of Typical Soda Lime Float Glass
id: National Glass Association, Glass Technical Paper FM05-12
url: https://www.glass.org/sites/default/files/2023-07/FM05-12_2023_Physical_Mechanical_Properties_Typical_Soda_Lime_Float_Glass.pdf
kind: report
year: 2023
license: trade association paper, cited not reproduced
wikipedia-soda-lime:
title: Soda-lime glass
id: Wikipedia, Soda-lime glass
url: https://en.wikipedia.org/wiki/Soda%E2%80%93lime_glass
kind: web
license: CC BY-SA 4.0
usgs-soda-ash:
title: 'Mineral Commodity Summaries 2026: Soda ash'
id: USGS, MCS 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-soda-ash.pdf
kind: report
year: 2026
license: US government work, public domain
usgs-industrial-sand:
title: 'Mineral Commodity Summaries 2026: Sand and gravel (industrial)'
id: USGS, MCS 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-sand-industrial.pdf
kind: report
year: 2026
license: US government work, public domain
pubchem-sodium-carbonate:
title: Sodium carbonate, PubChem CID 10340
id: PubChem, GHS classification of sodium carbonate
url: https://pubchem.ncbi.nlm.nih.gov/compound/10340
kind: database
license: PubChem, public domain
kugelpompel-soda-lime:
title: Data sheet Soda lime glass V1.01
id: Kugelpompel, soda-lime glass sphere data sheet
url: https://www.kugelpompel.at/img/cms/Datenbl%C3%A4tter%20Glas/Data%20sheet%20Soda-lime%20glass%20V1-01.pdf
kind: datasheet
year: 2020
license: manufacturer document, cited not reproduced
ronchetto-2019:
title: The effects of fatigue and weathering on the failure behavior of commercial soda-lime-silicate glass
id: Missouri S&T doctoral dissertation, Ronchetto, 2019
url: https://scholarsmine.mst.edu/doctoral_dissertations/2845
kind: paper
year: 2019
license: open-access thesis
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 20
unreachable: 1
caveats: 3
note: Written by an AI assistant on 2026-10-26 from sources read in this run. Continental Trade, Pilkington ATS-129, NGA FM05-12, Wikipedia, USGS soda ash and industrial sand, PubChem sodium carbonate, Kugelpompel and the Ronchetto 2019 dissertation. Two open papers could not be opened.
story:
recipe:
line: Soda-lime glass is an amorphous silica network modified by sodium and calcium oxides. Float glass is made from sand, soda ash, limestone, dolomite and salt cake, with about 20% recycled glass (cullet). Pilkington says making glass from cullet takes half the energy of making it from raw materials. The composition below is a typical sheet composition from Continental Trade. No producer's exact batch recipe is published.
parts:
- name: Silica
symbol: SiO2
share: about 72.6%
role: The main network former. It gives the glass its rigid, mostly silica framework.
share_percent: 72.6
- name: Sodium oxide
symbol: Na2O
share: about 13.9%
role: Added as soda ash (sodium carbonate). It lowers the melting temperature of the silica.
share_percent: 13.9
- name: Calcium oxide
symbol: CaO
share: about 8.4%
role: Added as limestone. It stabilises the glass network.
share_percent: 8.4
- name: Magnesium oxide
symbol: MgO
share: about 3.9%
role: Comes in with the dolomite in the batch.
share_percent: 3.9
- name: Aluminium oxide
symbol: Al2O3
share: about 1.1%
role: Minor oxide in the typical sheet composition.
share_percent: 1.1
- name: Recycled glass
symbol: cullet
share: about 20% of float glass
role: Broken glass put back into the batch as a melting aid.
share_percent: 20
source: continental-trade-sheet
where: Composition list (Continental Trade); raw materials list and cullet paragraph (Pilkington ATS-129, pages 2 and 3)
risk_groups:
- title: For people
level: 0
verdict: 'Hazard data partly checked: PubChem''s classes for the raw…'
lead: No source opened in this run classes the finished glass. The only classes read are for its raw material, sodium carbonate (H319, eye irritation). No SDS for the finished glass was opened.
points:
- label: Sharp edges
line: Broken glass is sharp. Handle broken pieces with gloves and dispose of them in a sharps container.
- label: Soda ash powder
line: PubChem's aggregated GHS for sodium carbonate is H319, causes serious eye irritation (Warning, 100% of reports). This describes the powder, not the finished glass.
- label: Heat
line: 'Keep the glass below its working limits: 110 °C not toughened and 150 °C toughened (Continental Trade).'
why: Soda-lime glass is the most common glass. Soda and lime added to silica lower the melting temperature, which keeps production cheap. Wikipedia says it accounts for about 90% of manufactured glass. The trade-off is a high thermal expansion, so Continental Trade says the glass has low resistance to sudden temperature changes.
uses:
- where: Windows
line: Wikipedia gives windowpanes as the main use of flat soda-lime glass, and says the float process makes window glass.
- where: Containers
line: Wikipedia says container glass is used for beverages and food, where its durability is required for storage.
- where: Valves and bearings
line: Kugelpompel sells soda-lime glass spheres for special bearings and valves, mixers, metering pumps and flow meters.
can_do:
- label: Density
benchmark: density
value: 2500 kg/m3
line: Continental Trade gives 2500 kg/m3 at 18 °C. Pilkington gives the same figure.
- label: Working temperature
benchmark: max_service_temp
value: 110 °C not toughened
line: Continental Trade gives a working limit of 110 °C for not-toughened glass and 150 °C for toughened glass.
- label: Softening point
benchmark: softening_point
value: 715 °C
line: Pilkington gives 715 °C (ASTM C338) for float glass. The NGA paper gives 715 to 729 °C.
- label: Bending strength
benchmark: flexural_strength
value: 165 MPa fully tempered
line: Pilkington's mean bending strength is 41 MPa for annealed glass, 83 MPa for heat-strengthened and 165 MPa for fully tempered glass.
- label: Optics
benchmark: refractive_index
value: '1.523'
line: Pilkington gives 1.523 for the sodium D line.
compare: Soda-lime float glass has a linear thermal expansion of 8.3 x10^-6 /°C (Pilkington, 75 to 575 °F), and Wikipedia gives 9.5 ppm/K for the flat-glass column. Its working limits are 110 °C for not-toughened glass and 150 °C for toughened glass, with a softening point of 715 °C. Those limits and its annealing point of 548 °C set the practical ceiling for most uses. Its bending strength depends strongly on temper.
compare_rows:
- scope: material
label: Density
benchmark: density
- scope: material
label: Softening point
benchmark: softening_point
- scope: material
label: Linear thermal expansion
benchmark: cte
handling:
- Keep not-toughened soda-lime glass below 110 °C and toughened glass below 150 °C (Continental Trade working limits).
- Keep temperature differences within 50 °C for not-toughened glass and 118 °C for toughened glass (Continental Trade thermal shock list).
- Keep the glass away from alkaline solutions. NGA rates acid resistance as excellent, except to hydrofluoric acid.
good_for:
- Windows and container glass, where low cost and wide supply matter more than high-temperature or thermal-shock performance.
- Spheres for valves and bearings, where chemical inertness and a smooth surface are needed (Kugelpompel).
watch_out:
- The thermal expansion is high. Continental Trade says the glass has low resistance to sudden temperature changes.
- 'Bending strength depends strongly on temper: annealed glass has a design stress of 19 MPa against a mean of 41 MPa (Pilkington).'
- Humidity can cut the failure strain of soda-lime-silicate glass (Ronchetto 2019, 80% RH at 50 °C for 28 days). Ageing of sheet glass in service is not covered by the sources read here.
verdict: Soda-lime glass is the low-cost default for windows and containers. The sources agree on density, expansion and the softening point, and they give clear working and thermal-shock limits. Its weak points are alkali resistance and thermal shock. No flight, radiation or vacuum result was found.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Soda-lime glass properties (information sheet) | datasheet | 7 values | ||
| ATS-129 Properties of soda-lime silica float glass | datasheet | 2025 | 16 values | |
| FM05-12 (2023) Physical and Mechanical Properties of Typical Soda Lime Float Glass | report | 2023 | 5 values | |
| Soda-lime glass | web | 2 values | ||
| Mineral Commodity Summaries 2026: Soda ash | report | 2026 | 2 values | |
| Mineral Commodity Summaries 2026: Sand and gravel (industrial) | report | 2026 | 1 value | |
| Sodium carbonate, PubChem CID 10340 | database | 1 value | ||
| Data sheet Soda lime glass V1.01 | datasheet | 2020 | 1 value | |
| The effects of fatigue and weathering on the failure behavior of commercial soda-lime-silicate glass | paper | 2019 | 3 values |