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C578 Type XI vs XPS 300

Polymer · grade comparison

C578 Type XI and XPS 300 are both polymer grades. XPS 300 is the stronger of the two: tensile strength 0.45 MPa (0.0653 ksi) against 0.08 MPa (0.0116 ksi) for C578 Type XI, about 5.6 times as much. XPS 300 is the more ductile: elongation 3% versus 2.5% for C578 Type XI. C578 Type XI is lighter (0.01 g/cm³ vs 0.04 g/cm³ for XPS 300) and XPS 300 is stiffer (0.02 GPa vs 0 GPa). On the shop floor, XPS 300 machines more easily (excellent vs good) and C578 Type XI welds better (25 vs 15 out of 100).

C578 Type XIChoose it when weight is the constraint, or when it will be welded.

XPS 300Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C578 Type XI vs XPS 300: properties

C578 Type XIXPS 300

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0 GPa3.19×10⁻⁴ Msi
0.02 GPa0 Msi

Poisson's Ratio

0.1
0.3

Tensile Strength (Ultimate)

0.08 MPa0.01 ksi
0.45 MPa0.07 ksi

Elongation at Break

2.5%
3%

Compressive Strength

0.04 MPa0.01 ksi
0.32 MPa0.05 ksi

Compressive Modulus

0 GPa2.32×10⁻⁴ Msi
0.01 GPa0 Msi

Flexural Strength

0.08 MPa0.01 ksi
0.55 MPa0.08 ksi

Flexural Modulus

0 GPa2.61×10⁻⁴ Msi
0.01 GPa0 Msi

Shear Strength

0.05 MPa0.01 ksi
0.25 MPa0.04 ksi

Yield Strength (0.2% offset)

—
0.3 MPa0.04 ksi

Physical

Density and transition temperatures.

Density

0.01 g/cm³4.34×10⁻⁴ lb/in³
0.04 g/cm³0 lb/in³

Water Absorption (24 h)

1%
0.2%

Water Absorption (Saturation)

3.5%
0.5%

Same in both: Glass Transition (Tg) 100°C212 °F

Thermal

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

Thermal Conductivity

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

Specific Heat Capacity

1,300 J/kg·K0.31 BTU/lb·°F
1,450 J/kg·K0.35 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

65 µm/m·K36.1 µin/in·°F
70 µm/m·K38.9 µin/in·°F

Vicat Softening Point (B50)

98°C208 °F
95°C203 °F

Limiting Oxygen Index

26%
25%

Max Service Temperature (short-term)

90°C194 °F
85°C185 °F

Same in both: Max Service Temperature (continuous) 75°C167 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Dielectric Constant (1 MHz)

1.03
1.07

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).

Same in both: Corrosion Resistance 85 / 100 · UV / Weathering Resistance 15 / 100

Manufacturability

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

Machinability

55 / 100
92 / 100

Weldability

25 / 100
15 / 100

Formability (cold)

15 / 100
10 / 100

Mold Shrinkage

0.5%
—

Processing Melt Temperature (typ.)

—
190°C374 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
100 MJ/kg42,992 BTU/lb

Embodied Carbon (primary production)

3.3 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

5%
15%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

7 kN·m/kg
13 kN·m/kg

Specific Stiffness (E / density)

0.2 MN·m/kg
0.4 MN·m/kg

Thermal Diffusivity

2.5 mm²/s
0.7 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 scaleXPS 300

Manufacturing and finishing

CapabilityC578 Type XIXPS 300
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

C578 Type XI vs XPS 300 — frequently asked

Is XPS 300 stronger than C578 Type XI?

Yes. XPS 300 has a typical tensile strength of 0.45 MPa (0.0653 ksi) against 0.08 MPa (0.0116 ksi) for C578 Type XI — about 5.6 times as much.

Which is cheaper, C578 Type XI or XPS 300?

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 XI or XPS 300?

XPS 300. Its machinability rates excellent (92/100) against good (55/100) for C578 Type XI; for welding the order is C578 Type XI first (poor, 25/100) then XPS 300 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C578 Type XI and XPS 300 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.