BIIR vs TPE
Polymer · grade comparison
BIIR and TPE are both polymer grades. BIIR is the stronger of the two: tensile strength 11 MPa (1.6 ksi) against 8 MPa (1.09 ksi) for TPE, about 47% more. TPE is harder — 20 Shore D against 15 Shore D for BIIR — which matters for wear surfaces and threads. TPE is lighter (0.96 g/cm³ vs 1.13 g/cm³ for BIIR) and TPE is stiffer (0.01 GPa vs 0 GPa). On the shop floor, TPE welds better (good vs poor).
BIIRChoose it when strength drives the design, or when the part sees heat.
TPEChoose it when surface hardness matters, or when weight is the constraint.
BIIR 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
Shear Strength
Hardness, Shore A
Hardness, Shore D
Tear Strength
Compression Set (22 h, 70 °C)
Compressive Strength
Flexural Modulus
Same in both: Bulk Modulus 2 GPa0.29 Msi
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Refractive Index
Melting Temperature (Tm)
Water Absorption (Saturation)
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
Limiting Oxygen Index
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Vicat Softening Point (B50)
Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Volume Resistivity 1×10¹⁵ Ω·cm
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)
Mold Shrinkage
Mold Temperature (typ.)
Polishability
Melt Flow Rate
Processing Melt Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Same in both: Embodied Carbon (primary production) 3.6 kg CO₂/kg · 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 | BIIR | TPE |
|---|---|---|
| Injection molding | — | Yes |
| Default condition | — | Shore A 30 to Shore A 90 |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Chrome Plating (Plastic) | — | Yes |
| EMI Shielding Coating | — | Yes |
| Soft Touch Coating | — | Yes |
| Spray Painting | — | Yes |
| UV Coating | — | Yes |
BIIR vs TPE — frequently asked
Is BIIR stronger than TPE?
Yes. BIIR has a typical tensile strength of 11 MPa (1.6 ksi) against 8 MPa (1.09 ksi) for TPE — about 47% more.
Which is cheaper, BIIR 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, BIIR or TPE?
BIIR, 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 BIIR (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in BIIR 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.