C578 Type VIII vs XPS 400
Polymer · grade comparison
C578 Type VIII and XPS 400 are both polymer grades. XPS 400 is the stronger of the two: tensile strength 0.6 MPa (0.087 ksi) against 0.2 MPa (0.029 ksi) for C578 Type VIII, about 200% more. C578 Type VIII is lighter (0.02 g/cm³ vs 0.04 g/cm³ for XPS 400) and XPS 400 is stiffer (0.02 GPa vs 0 GPa).
C578 Type VIIIChoose it when weight is the constraint.
XPS 400Choose it when strength drives the design.
C578 Type VIII vs XPS 400: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer 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 polymer 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
Poisson's Ratio
Tensile Strength (Ultimate)
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Yield Strength (0.2% offset)
Compression Set (22 h, 70 °C)
Same in both: Elongation at Break 2.5%
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Water Absorption (Saturation)
Same in both: Glass Transition (Tg) 100°C212 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Max Service Temperature (continuous) 75°C167 °F · Min Service Temperature -50°C-58 °F · Limiting Oxygen Index 25%
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Volume Resistivity
Same in both: Dissipation Factor (1 MHz) 3×10⁻⁴
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 70 / 100 · UV / Weathering Resistance 15 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Processing Melt Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | C578 Type VIII | XPS 400 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
C578 Type VIII vs XPS 400 — frequently asked
Is XPS 400 stronger than C578 Type VIII?
Yes. XPS 400 has a typical tensile strength of 0.6 MPa (0.087 ksi) against 0.2 MPa (0.029 ksi) for C578 Type VIII — about 200% more.
Which is cheaper, C578 Type VIII or XPS 400?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, C578 Type VIII or XPS 400?
XPS 400, by a small margin. Both rate excellent for machinability — 92/100 against 85/100 for C578 Type VIII; for welding the order is C578 Type VIII first (poor, 20/100) then XPS 400 (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C578 Type VIII and XPS 400 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.