ABS vs EPS
Polymer · grade comparison
ABS and EPS are both polymer grades. ABS is the stronger of the two: yield strength 42 MPa (6.09 ksi) against 0.2 MPa (0.029 ksi) for EPS, about 210 times as much; tensile strength follows at 43 MPa (6.24 ksi) vs 0.25 MPa (0.0363 ksi). ABS is the more ductile: elongation 25% versus 3% for EPS. EPS is lighter (0.02 g/cm³ vs 1.04 g/cm³ for ABS) and ABS is stiffer (2.3 GPa vs 0.01 GPa). On the shop floor, EPS machines more easily (excellent vs very good) and ABS welds better (very good vs fair).
ABSChoose 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.
ABS 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
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
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
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Max Service Temperature (continuous) 75°C167 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Comparative Tracking Index (CTI)
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
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
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 | ABS | EPS |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| 3D printing | Yes | — |
| Default condition | Unfilled | — |
| Relative cost | $ Budget | $ 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 | — |
ABS vs EPS — frequently asked
Is ABS stronger than EPS?
Yes. ABS has a typical yield strength of 42 MPa (6.09 ksi) against 0.2 MPa (0.029 ksi) for EPS — about 210 times as much. Tensile strength is 43 MPa (6.24 ksi) vs 0.25 MPa (0.0363 ksi).
Which is cheaper, ABS or EPS?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, ABS or EPS?
EPS. Its machinability rates excellent (90/100) against very good (80/100) for ABS; for welding the order is ABS first (very good, 78/100) then EPS (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ABS 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.