Mycalex vs Robax
Glass · grade comparison
Mycalex and Robax are both glass grades. Mycalex is the stronger of the two: tensile strength 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Robax, about 29% more. Mycalex is the more ductile: elongation 0.1% versus 0% for Robax, and Robax is harder (590 HV vs 250 HV). Robax is lighter (2.55 g/cm³ vs 3.4 g/cm³ for Mycalex) and Robax is stiffer (92 GPa vs 65 GPa). On the shop floor, Mycalex machines more easily (very good vs not recommended) and Robax sits in a lower cost tier (standard, $$) than Mycalex (high, $$$$).
MycalexChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
RobaxChoose it when weight is the constraint, or when the part sees heat.
Mycalex vs Robax: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Vickers
Hardness, Knoop
Hardness, Mohs
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)
Same in both: Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
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
Polishability
Sintering / Firing Temperature
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 2.2 kg CO₂/kg
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
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 | Mycalex | Robax |
|---|---|---|
| Default condition | — | Annealed Glass |
| Relative cost | $$$$ High | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Mycalex vs Robax — frequently asked
Is Mycalex stronger than Robax?
Yes. Mycalex has a typical tensile strength of 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Robax — about 29% more.
Which is cheaper, Mycalex or Robax?
Robax is the lower-cost material: it sits in the standard tier ($$) while Mycalex is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, Mycalex or Robax?
Mycalex. Its machinability rates very good (75/100) against not recommended (6/100) for Robax.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Mycalex and Robax 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.