E-51 vs Epoxy
Polymer · grade comparison
E-51 and Epoxy are both polymer grades. Epoxy runs hotter in service (130°C vs 95°C continuous).
EpoxyChoose it when the part sees heat.
E-51 vs Epoxy: 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.
Shear Modulus
Bulk Modulus
Compressive Modulus
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Same in both: Elastic (Young's) Modulus 3 GPa0.44 Msi · Poisson's Ratio 0.35 · Tensile Strength (Ultimate) 65 MPa9.4 ksi · Elongation at Break 4% · Compressive Strength 110 MPa16 ksi · Flexural Strength 110 MPa16 ksi · Flexural Modulus 3 GPa0.44 Msi · Shear Strength 45 MPa6.5 ksi · Hardness, Rockwell M 100 HRM
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Same in both: Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 1.6% · Refractive Index 1.56 · Light Transmission 88%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Dielectric Strength 20 kV/mm508 V/mil · Dielectric Constant (1 MHz) 3.6 · Dissipation Factor (1 MHz) 0.02 · Volume Resistivity 1×10¹⁵ Ω·cm · Surface Resistivity 1×10¹⁴ Ω
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Polishability
Mold Shrinkage
Mold Temperature (typ.)
Weldability
Formability (cold)
Same in both: Machinability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 137 MJ/kg58,899 BTU/lb · Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
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 | E-51 | Epoxy |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
E-51 vs Epoxy — frequently asked
What is the difference between E-51 and Epoxy?
E-51 and Epoxy are both polymer grades. Epoxy runs hotter in service (130°C vs 95°C continuous).
Which is cheaper, E-51 or Epoxy?
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.
When should I choose E-51 over Epoxy?
Pick Epoxy when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in E-51 and Epoxy 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.