EPDM vs TPE
Polymer · grade comparison
EPDM and TPE are both polymer grades. EPDM is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 8 MPa (1.09 ksi) for TPE, about 60% more. In exchange, TPE is the more ductile: elongation 480% versus 400% for EPDM, and EPDM is harder (22 Shore D vs 20 Shore D). TPE is lighter (0.96 g/cm³ vs 1.15 g/cm³ for EPDM) and TPE is stiffer (0.01 GPa vs 0.01 GPa). On the shop floor, TPE welds better (good vs poor).
EPDMChoose it when strength drives the design, or when the part sees heat.
TPEChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
EPDM vs TPE: 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)
Elongation at Break
Hardness, Shore A
Hardness, Shore D
Compression Set (22 h, 70 °C)
Compressive Strength
Flexural Modulus
Shear Strength
Same in both: Bulk Modulus 2 GPa0.29 Msi · Tear Strength 25 kN/m143 lbf/in
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Melting Temperature (Tm)
Water Absorption (Saturation)
Same in both: Glass Transition (Tg) -55°C-67 °F
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)
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Vicat Softening Point (B50)
Same in both: Min Service Temperature -50°C-58 °F · Limiting Oxygen Index 19%
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume 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
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Melt Flow Rate
Same in both: Formability (cold) 90 / 100 · Polishability 20 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 95 MJ/kg40,843 BTU/lb · Typical Recycled Content 5%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 0 MN·m/kg · Thermal Diffusivity 0.1 mm²/s
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 | EPDM | TPE |
|---|---|---|
| Default condition | Solid | Shore A 30 to Shore A 90 |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both are offered for Injection molding. Both take the same 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.
EPDM vs TPE — frequently asked
Is EPDM stronger than TPE?
Yes. EPDM has a typical tensile strength of 12 MPa (1.74 ksi) against 8 MPa (1.09 ksi) for TPE — about 60% more.
Which is cheaper, EPDM or TPE?
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, EPDM or TPE?
EPDM, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for TPE; for welding the order is TPE first (good, 65/100) then EPDM (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in EPDM and TPE 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.