Cast Silicone vs FVMQ
Silicone · grade comparison
Cast Silicone and FVMQ are both silicone grades. FVMQ is the stronger of the two: tensile strength 9 MPa (1.23 ksi) against 5 MPa (0.725 ksi) for Cast Silicone, about 70% more. In exchange, Cast Silicone is the more ductile: elongation 400% versus 250% for FVMQ. Cast Silicone is lighter (1.1 g/cm³ vs 1.45 g/cm³ for FVMQ) and FVMQ is stiffer (0.01 GPa vs 0 GPa). On the shop floor, Cast Silicone sits in a lower cost tier (standard, $$) than FVMQ (high, $$$$).
Cast SiliconeChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
FVMQChoose it when strength drives the design.
Cast Silicone vs FVMQ: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all silicone 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 silicone 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
Tensile Strength (Ultimate)
Elongation at Break
Hardness, Shore A
Tear Strength
Compression Set (22 h, 70 °C)
Hardness, Shore D
Same in both: Poisson's Ratio 0.49
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Min Service Temperature
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Max Service Temperature (continuous) 200°C392 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Same in both: Dielectric Strength 20 kV/mm508 V/mil · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 85 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Formability (cold)
Polishability
Mold Shrinkage
Mold Temperature (typ.)
Same in both: Machinability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Same in both: Specific Stiffness (E / density) 0 MN·m/kg · Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 2
Strength versus weight
Yield strength against density for every silicone grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Cast Silicone | FVMQ |
|---|---|---|
| Urethane casting | Yes | — |
| Default condition | Shore A 40 | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Cast Silicone vs FVMQ — frequently asked
Is FVMQ stronger than Cast Silicone?
Yes. FVMQ has a typical tensile strength of 9 MPa (1.23 ksi) against 5 MPa (0.725 ksi) for Cast Silicone — about 70% more.
Which is cheaper, Cast Silicone or FVMQ?
Cast Silicone is the lower-cost material: it sits in the standard tier ($$) while FVMQ is high ($$$$). 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 Cast Silicone over FVMQ?
Pick Cast Silicone when the part is bent, formed or impact-loaded, or when weight is the constraint. Pick FVMQ when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Cast Silicone and FVMQ 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.