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.