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C578 Type VIII vs JIS A9511 EPS

Polymer · grade comparison

C578 Type VIII and JIS A9511 EPS are both polymer grades. C578 Type VIII is the more ductile: elongation 2.5% versus 1.5% for JIS A9511 EPS. C578 Type VIII is lighter (0.02 g/cm³ vs 0.02 g/cm³ for JIS A9511 EPS) and JIS A9511 EPS is stiffer (0.01 GPa vs 0 GPa). On the shop floor, JIS A9511 EPS welds better (30 vs 20 out of 100).

C578 Type VIIIChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

JIS A9511 EPSChoose it when it will be welded.

C578 Type VIII vs JIS A9511 EPS: properties

C578 Type VIIIJIS A9511 EPS

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0 GPa6.53×10⁻⁴ Msi
0.01 GPa7.25×10⁻⁴ Msi

Shear Modulus

0 GPa2.9×10⁻⁴ Msi
—

Elongation at Break

2.5%
1.5%

Compressive Strength

0.1 MPa0.01 ksi
0.08 MPa0.01 ksi

Compressive Modulus

0 GPa5.8×10⁻⁴ Msi
0 GPa6.53×10⁻⁴ Msi

Flexural Strength

0.24 MPa0.03 ksi
0.15 MPa0.02 ksi

Flexural Modulus

0.01 GPa7.25×10⁻⁴ Msi
0.01 GPa7.98×10⁻⁴ Msi

Shear Strength

0.11 MPa0.02 ksi
0.1 MPa0.01 ksi

Yield Strength (0.2% offset)

—
0.18 MPa0.03 ksi

Compression Set (22 h, 70 °C)

—
4%

Same in both: Poisson's Ratio 0.1 · Tensile Strength (Ultimate) 0.2 MPa0.03 ksi

Physical

Density and transition temperatures.

Density

0.02 g/cm³6.86×10⁻⁴ lb/in³
0.02 g/cm³7.23×10⁻⁴ lb/in³

Water Absorption (Saturation)

3%
4%

Same in both: Glass Transition (Tg) 100°C212 °F · Water Absorption (24 h) 1.5%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.04 W/m·K0.02 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F

Specific Heat Capacity

1,300 J/kg·K0.31 BTU/lb·°F
1,400 J/kg·K0.33 BTU/lb·°F

Min Service Temperature

-50°C-58 °F
-80°C-112 °F

Vicat Softening Point (B50)

100°C212 °F
98°C208 °F

Limiting Oxygen Index

25%
18%

Max Service Temperature (short-term)

95°C203 °F
85°C185 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 65 µm/m·K36.1 µin/in·°F · Max Service Temperature (continuous) 75°C167 °F

Electrical

Conductivity and insulation.

Dielectric Constant (1 MHz)

1.03
1.04

Dissipation Factor (1 MHz)

3×10⁻⁴
2×10⁻⁴

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
80 / 100

Same in both: UV / Weathering Resistance 15 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

85 / 100
90 / 100

Weldability

20 / 100
30 / 100

Formability (cold)

15 / 100
25 / 100

Mold Shrinkage

0.8%
0.45%

Mold Temperature (typ.)

—
115°C239 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Water

180 L/kg21.6 gal/lb
165 L/kg19.8 gal/lb

Same in both: Embodied Energy (primary production) 105 MJ/kg45,142 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Typical Recycled Content 5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

11 kN·m/kg
10 kN·m/kg

Specific Stiffness (E / density)

0.2 MN·m/kg
0.3 MN·m/kg

Thermal Diffusivity

1.5 mm²/s
1.4 mm²/s

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scaleJIS A9511 EPS

Manufacturing and finishing

CapabilityC578 Type VIIIJIS A9511 EPS
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

C578 Type VIII vs JIS A9511 EPS — frequently asked

What is the difference between C578 Type VIII and JIS A9511 EPS?

C578 Type VIII and JIS A9511 EPS are both polymer grades. C578 Type VIII is the more ductile: elongation 2.5% versus 1.5% for JIS A9511 EPS. C578 Type VIII is lighter (0.02 g/cm³ vs 0.02 g/cm³ for JIS A9511 EPS) and JIS A9511 EPS is stiffer (0.01 GPa vs 0 GPa).

Which is cheaper, C578 Type VIII or JIS A9511 EPS?

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 JIS A9511 EPS?

JIS A9511 EPS, by a small margin. Both rate excellent for machinability — 90/100 against 85/100 for C578 Type VIII; for welding the order is JIS A9511 EPS first (poor, 30/100) then C578 Type VIII (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C578 Type VIII and JIS A9511 EPS 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.