Alumina-Lime-Silica Glass (IEC G-400) vs Pyrex 7740
Glass · grade comparison
Alumina-Lime-Silica Glass (IEC G-400) and Pyrex 7740 are both glass grades. Alumina-Lime-Silica Glass (IEC G-400) is the stronger of the two: tensile strength 60 MPa (8.7 ksi) against 35 MPa (5.08 ksi) for Pyrex 7740, about 71% more. Alumina-Lime-Silica Glass (IEC G-400) is harder — 620 HV against 480 HV for Pyrex 7740 — which matters for wear surfaces and threads. Pyrex 7740 is lighter (2.23 g/cm³ vs 2.6 g/cm³ for Alumina-Lime-Silica Glass (IEC G-400)) and Alumina-Lime-Silica Glass (IEC G-400) is stiffer (87 GPa vs 64 GPa).
Alumina-Lime-Silica Glass (IEC G-400)Choose it when strength drives the design, or when surface hardness matters.
Pyrex 7740Choose it when weight is the constraint.
Alumina-Lime-Silica Glass (IEC G-400) vs Pyrex 7740: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all glass grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all glass grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Alumina-Lime-Silica Glass (IEC G-400)Pyrex 7740
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Vickers
Hardness, Knoop
Hardness, Mohs
Same in both: Elongation at Break 0% · Compressive Strength 1,000 MPa145 ksi
Physical
Density and transition temperatures.
Density
Refractive Index
Light Transmission
Same in both: Porosity 0%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Volume Resistivity 1×10¹⁵ Ω·cm
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Same in both: Machinability 12 / 100 · Polishability 96 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every glass grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Alumina-Lime-Silica Glass (IEC G-400) | Pyrex 7740 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Alumina-Lime-Silica Glass (IEC G-400) vs Pyrex 7740 — frequently asked
Is Alumina-Lime-Silica Glass (IEC G-400) stronger than Pyrex 7740?
Yes. Alumina-Lime-Silica Glass (IEC G-400) has a typical tensile strength of 60 MPa (8.7 ksi) against 35 MPa (5.08 ksi) for Pyrex 7740 — about 71% more.
Which is cheaper, Alumina-Lime-Silica Glass (IEC G-400) or Pyrex 7740?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose Alumina-Lime-Silica Glass (IEC G-400) over Pyrex 7740?
Pick Alumina-Lime-Silica Glass (IEC G-400) when strength drives the design, or when surface hardness matters. Pick Pyrex 7740 when weight is the constraint.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alumina-Lime-Silica Glass (IEC G-400) and Pyrex 7740 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.