Ultem 2300 vs Vespel SP-1
Polymer · grade comparison
Ultem 2300 and Vespel SP-1 are both polymer grades. Ultem 2300 is the stronger of the two: tensile strength 169 MPa (24.5 ksi) against 86 MPa (12.5 ksi) for Vespel SP-1, about 97% more. In exchange, Vespel SP-1 is the more ductile: elongation 7.5% versus 3% for Ultem 2300. Vespel SP-1 is lighter (1.43 g/cm³ vs 1.51 g/cm³ for Ultem 2300) and Ultem 2300 is stiffer (9 GPa vs 2.5 GPa). On the shop floor, Ultem 2300 welds better (fair vs not recommended).
Ultem 2300Choose it when strength drives the design, or when it will be welded.
Vespel SP-1Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
Ultem 2300 vs Vespel SP-1: 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)
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, Rockwell M
Same in both: Hardness, Shore D 90 Shore D
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)
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.
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.
Weldability
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Machinability 55 / 100 · Formability (cold) 10 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Same in both: Thermal Diffusivity 0.2 mm²/s · 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 | Ultem 2300 | Vespel SP-1 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Ultem 2300 vs Vespel SP-1 — frequently asked
Is Ultem 2300 stronger than Vespel SP-1?
Yes. Ultem 2300 has a typical tensile strength of 169 MPa (24.5 ksi) against 86 MPa (12.5 ksi) for Vespel SP-1 — about 97% more.
Which is cheaper, Ultem 2300 or Vespel SP-1?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, Ultem 2300 or Vespel SP-1?
Ultem 2300. Its weldability rates fair (45/100) against not recommended (5/100) for Vespel SP-1.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Ultem 2300 and Vespel SP-1 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.