Alumina-Lime-Silica Glass (IEC G-400)
ISO IEC 60672-3 G-400
Alumina-Lime-Silica Glass (IEC G-400) is a lime-silica glass enriched with alumina, which raises the softening point and electrical resistivity above standard soda-lime; it is on file annealed (ANN), tempered (TEMP) and chemically strengthened (CS).
Reference datasheet — Alumina-Lime-Silica Glass (IEC G-400) is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
Alumina-Lime-Silica Glass (IEC G-400) tempers and conditions
Alumina-Lime-Silica Glass (IEC G-400) is supplied in 3 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard supply state for tubing, bulbs, sealing parts and windows where the glass will be further worked or sealed. | 60 | 0 | 620 HV | 1 W/m·K | |
Thermally tempered | Choose when mechanical or thermal-shock loading is high and no post-forming cutting or flame sealing is required. | 150 | 0 | 620 HV | 1 W/m·K | |
Chemically strengthened | Choose for thin (<3 mm) cover glass, windows and lamp parts needing very high scratch and bending strength; strengthening relaxes above ~350 °C. | 300 | 0 | 660 HV | 1 W/m·K |
What is Alumina-Lime-Silica Glass (IEC G-400)?
Alumina-Lime-Silica Glass (IEC G-400) is a lime-silica glass enriched with alumina, which raises the softening point and electrical resistivity above standard soda-lime; it is on file annealed (ANN), tempered (TEMP) and chemically strengthened (CS). It is used where lamp and electronics seals must survive heat, with a 650 °C maximum service temperature, about 60 MPa tensile strength and a low ~4.6 µm/m·K expansion that suits sealing to matched alloys. Melting at 1550–1650 °C makes it costlier to process than soda-lime and machinability is low (12); borosilicate covers similar thermal duty at lower cost. Alumina-Lime-Silica Glass (IEC G-400) has a density of 2.6 g/cm³ (0.0939 lb/in³), lighter than 57% of glass grades. Alumina-Lime-Silica Glass (IEC G-400) has a tensile strength of 60 MPa (8.7 ksi), stronger than 74% of glass grades. Elongation at break is 0% and the elastic modulus is 87 GPa (12.6 Msi).
What is Alumina-Lime-Silica Glass (IEC G-400) used for?
- incandescent/fluorescent lamp seals
- electrical insulator bodies
- fiberglass reinforcement precursor
Advantages
- Low embodied carbon — 1.6 kg CO₂/kg, better than 90% of glass grades
Alumina-Lime-Silica Glass (IEC G-400) properties
Typical room-temperature values for Alumina-Lime-Silica Glass (IEC G-400)-ANN; bars are the position among glass grades.
Physical4
Alumina-Lime-Silica Glass (IEC G-400) has a density of 2.6 g/cm³ (0.0939 lb/in³), lighter than 57% of glass grades.
Mechanical13
Alumina-Lime-Silica Glass (IEC G-400) has a tensile strength of 60 MPa (8.7 ksi), stronger than 74% of glass grades. Elongation at break is 0% and the elastic modulus is 87 GPa (12.6 Msi).
Thermal5
Alumina-Lime-Silica Glass (IEC G-400) is rated for continuous service to 650°C (1,202 °F). It conducts heat at 1.2 W/m·K (0.693 BTU/hr·ft·°F), worse than 58% of glass grades. Thermal expansion is 4.6 µm/m·K (2.56 µin/in·°F).
Electrical5
Alumina-Lime-Silica Glass (IEC G-400) is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (90/100), better than 73% of glass grades.
Sustainability4
Producing a kilogram of Alumina-Lime-Silica Glass (IEC G-400) takes about 25 MJ of energy and emits 1.6 kg of CO₂ — less than 88% of glass grades. Typical recycled content is 5%.
Manufacturability2
Alumina-Lime-Silica Glass (IEC G-400)'s machinability is not recommended (12/100, worse than 68% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the glass family
Yield strength against density for every glass grade FabDigit runs. Alumina-Lime-Silica Glass (IEC G-400) is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Alumina-Lime-Silica Glass (IEC G-400)
Is Alumina-Lime-Silica Glass (IEC G-400) easy to machine?
Cold work only by diamond grinding, ultrasonic drilling, water-jet or laser; anneal after heavy grinding and never machine tempered or ion-exchanged parts.
Can Alumina-Lime-Silica Glass (IEC G-400) be welded?
Joined by flame/lathe glass working near 1000–1100 °C or by glass-to-metal sealing with matched alloys; adjacent glasses must match the ~4.6 µm/m·K CTE.
Can Alumina-Lime-Silica Glass (IEC G-400) be formed, bent or molded?
Melted around 1550–1650 °C and drawn, blown or pressed at working point (~1150–1200 °C); higher furnace temperatures than soda-lime require Mo/Pt-lined melters.
Alumina-Lime-Silica Glass (IEC G-400) chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al2O3defines the G-400 group; raises softening point and resistivity | 14 – 25 | 18 |
| CaO | 5 – 13 | 9 |
| MgO | 3 – 10 | 7 |
| B2O3optional melting aid | 0 – 6 | 4 |
| BaOvariant dependent | 0 – 8 | 4 |
| Na2O+K2Okept low for high electrical resistivity (higher, 12–16 %, in ion-exchangeable cover-glass variants) | 0 – 2 | 0.6 |
| SiO2network former | ≥ 52 (balance) |
What surface finishes work on Alumina-Lime-Silica Glass (IEC G-400)?
Fire-polishing, acid polishing, optical lapping, ion exchange in KNO₃ (~420 °C) or thin-film/ITO coating are all standard.
Equivalent designations
Standards and trade names that resolve to Alumina-Lime-Silica Glass (IEC G-400) in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- IEC 60672-3 G-400
How much does Alumina-Lime-Silica Glass (IEC G-400) cost?
Alumina-Lime-Silica Glass (IEC G-400) is a premium-cost glass ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Alumina-Lime-Silica Glass (IEC G-400) — frequently asked
What is Alumina-Lime-Silica Glass (IEC G-400) used for?
Alumina-Lime-Silica Glass (IEC G-400) is typically used for incandescent/fluorescent lamp seals, electrical insulator bodies and fiberglass reinforcement precursor. In short: highest-temperature lime-silica glass; low 4.6 µm/m·K expansion; strongest annealed glass here.
What is the tensile strength of Alumina-Lime-Silica Glass (IEC G-400)?
Alumina-Lime-Silica Glass (IEC G-400) has a typical tensile strength of 60 MPa (8.7 ksi) — stronger than 74% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is Alumina-Lime-Silica Glass (IEC G-400) easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 68% of glass grades). Cold work only by diamond grinding, ultrasonic drilling, water-jet or laser; anneal after heavy grinding and never machine tempered or ion-exchanged parts.
Can Alumina-Lime-Silica Glass (IEC G-400) be welded?
Joined by flame/lathe glass working near 1000–1100 °C or by glass-to-metal sealing with matched alloys; adjacent glasses must match the ~4.6 µm/m·K CTE.
What surface finishes work on Alumina-Lime-Silica Glass (IEC G-400)?
Fire-polishing, acid polishing, optical lapping, ion exchange in KNO₃ (~420 °C) or thin-film/ITO coating are all standard.
Can Alumina-Lime-Silica Glass (IEC G-400) be formed, bent or molded?
Melted around 1550–1650 °C and drawn, blown or pressed at working point (~1150–1200 °C); higher furnace temperatures than soda-lime require Mo/Pt-lined melters.
What is the maximum service temperature of Alumina-Lime-Silica Glass (IEC G-400)?
Alumina-Lime-Silica Glass (IEC G-400) is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Alumina-Lime-Silica Glass (IEC G-400) cost?
Alumina-Lime-Silica Glass (IEC G-400) is a premium-cost glass ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- IEC 60672-3 Ceramic and glass insulating materials – Part 3: Specifications for individual materials (group G) — IEC (1997)
- Corning Code 1723 aluminosilicate glass properties — Corning Incorporated (2018)
- Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Technical glass properties (aluminosilicate / lamp glass) — SCHOTT AG (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.