Borofloat 33 vs Lead Glass (IEC G-500)
Glass · grade comparison
Borofloat 33 and Lead Glass (IEC G-500) are both glass grades. Lead Glass (IEC G-500) is the stronger of the two: tensile strength 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Borofloat 33, about 29% more. Borofloat 33 is harder — 480 HV against 420 HV for Lead Glass (IEC G-500) — which matters for wear surfaces and threads. Borofloat 33 is lighter (2.23 g/cm³ vs 3.1 g/cm³ for Lead Glass (IEC G-500)) and Borofloat 33 runs hotter in service (450°C vs 350°C continuous). On the shop floor, Borofloat 33 sits in a lower cost tier (standard, $$) than Lead Glass (IEC G-500) (premium, $$$).
Borofloat 33Choose it when surface hardness matters, or when weight is the constraint.
Lead Glass (IEC G-500)Choose it when strength drives the design.
Borofloat 33 vs Lead Glass (IEC G-500): 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.
Borofloat 33Lead Glass (IEC G-500)
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Compressive Strength
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Vickers
Hardness, Knoop
Hardness, Mohs
Same in both: Elongation at Break 0%
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.
Electrical Resistivity
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Same in both: Dielectric Strength 30 kV/mm762 V/mil
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.
Machinability
Same in both: Polishability 95 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 15 L/kg1.8 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Same in both: Thermal Diffusivity 0.6 mm²/s · 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 | Borofloat 33 | Lead Glass (IEC G-500) |
|---|---|---|
| Default condition | Annealed Glass | — |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Borofloat 33 vs Lead Glass (IEC G-500) — frequently asked
Is Lead Glass (IEC G-500) stronger than Borofloat 33?
Yes. Lead Glass (IEC G-500) has a typical tensile strength of 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Borofloat 33 — about 29% more.
Which is cheaper, Borofloat 33 or Lead Glass (IEC G-500)?
Borofloat 33 is the lower-cost material: it sits in the standard tier ($$) while Lead Glass (IEC G-500) is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose Borofloat 33 over Lead Glass (IEC G-500)?
Pick Borofloat 33 when surface hardness matters, or when weight is the constraint. Pick Lead Glass (IEC G-500) when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Borofloat 33 and Lead Glass (IEC G-500) 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.