ASA vs EPS
Polymer · grade comparison
ASA and EPS are both polymer grades. ASA is the stronger of the two: yield strength 45 MPa (6.53 ksi) against 0.2 MPa (0.029 ksi) for EPS, about 225 times as much; tensile strength follows at 47 MPa (6.82 ksi) vs 0.25 MPa (0.0363 ksi). ASA is the more ductile: elongation 25% versus 3% for EPS. EPS is lighter (0.02 g/cm³ vs 1.07 g/cm³ for ASA) and ASA is stiffer (2.2 GPa vs 0.01 GPa). On the shop floor, EPS machines more easily (excellent vs very good), ASA welds better (very good vs fair), and EPS sits in a lower cost tier (budget, $) than ASA (standard, $$).
ASAChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
EPSChoose it when weight is the constraint, or when the part is machined in volume.
ASA vs EPS: 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
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Compressive Modulus
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)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Surface Resistivity
Comparative Tracking Index (CTI)
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
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Mold Shrinkage 0.5%
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 5%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
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 | ASA | EPS |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| 3D printing | Yes | — |
| Default condition | Unfilled | — |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Chrome Plating (Plastic) | Yes | — |
| Conductive Coating | Yes | — |
| Dyeing (Nylon) | Yes | — |
| EMI Shielding Coating | Yes | — |
| Painting | Yes | — |
| Primer Coating | Yes | — |
| Soft Touch Coating | Yes | — |
| Spray Painting | Yes | — |
| Tinted Coating | Yes | — |
| UV Coating | Yes | — |
| Vacuum Metallization | Yes | — |
| Waterproof Coating | Yes | — |
ASA vs EPS — frequently asked
Is ASA stronger than EPS?
Yes. ASA has a typical yield strength of 45 MPa (6.53 ksi) against 0.2 MPa (0.029 ksi) for EPS — about 225 times as much. Tensile strength is 47 MPa (6.82 ksi) vs 0.25 MPa (0.0363 ksi).
Which is cheaper, ASA or EPS?
EPS is the lower-cost material: it sits in the budget tier ($) while ASA is standard ($$). 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, ASA or EPS?
EPS. Its machinability rates excellent (90/100) against very good (75/100) for ASA; for welding the order is ASA first (very good, 70/100) then EPS (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ASA and 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.