PBI vs PPS
Polymer · grade comparison
PBI and PPS are both polymer grades, both high performance plastic. PBI is the stronger of the two: tensile strength 160 MPa (23.2 ksi) against 78 MPa (11.3 ksi) for PPS, about 105% more. In exchange, PPS is the more ductile: elongation 5% versus 3% for PBI. PBI is lighter (1.3 g/cm³ vs 1.35 g/cm³ for PPS) and PBI is stiffer (5.9 GPa vs 3.8 GPa). On the shop floor, PPS machines more easily (good vs fair) and PPS welds better (poor vs not recommended).
PBIChoose it when strength drives the design, or when weight is the constraint.
PPSChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
PBI vs PPS: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Rockwell M
Shear Modulus
Yield Strength (0.2% offset)
Hardness, Shore D
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Melting Temperature (Tm)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 1.8 MPa
Limiting Oxygen Index
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Same in both: Specific Heat Capacity 1,000 J/kg·K0.24 BTU/lb·°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).
UV / Weathering Resistance
Same in both: Corrosion Resistance 92 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Typical Recycled Content
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
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 | PBI | PPS |
|---|---|---|
| Default condition | Unfilled | Unfilled |
| Relative cost | $$$$$ Specialty | $$$$$ Specialty |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining, Sheet metal and Injection molding. Both take the same 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
PBI vs PPS — frequently asked
Is PBI stronger than PPS?
Yes. PBI has a typical tensile strength of 160 MPa (23.2 ksi) against 78 MPa (11.3 ksi) for PPS — about 105% more.
Which is cheaper, PBI or PPS?
Both sit in the same relative cost tier ($$$$$, specialty); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PBI or PPS?
PPS. Its machinability rates good (60/100) against fair (50/100) for PBI; for welding the order is PPS first (poor, 30/100) then PBI (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PBI and PPS 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.