PEI vs. Spruce-pine-fir
PEI belongs to the thermoplastics classification, while spruce-pine-fir belongs to the wood-based materials. There are 16 material properties with values for both materials. Properties with values for just one material (15, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is PEI and the bottom bar is spruce-pine-fir.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 140 to 180 | |
| 50 |
| Elastic (Young's, Tensile) Modulus, GPa | 3.4 to 5.6 | |
| 16 |
| Elongation at Break, % | 3.0 to 34 | |
| 1.5 |
| Tensile Strength: Ultimate (UTS), MPa | 110 to 160 | |
| 85 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 170 | |
| 130 |
| Specific Heat Capacity, J/kg-K | 1050 to 1220 | |
| 1380 |
| Thermal Conductivity, W/m-K | 0.18 to 0.23 | |
| 0.12 |
| Thermal Expansion, µm/m-K | 20 to 53 | |
| 6.5 |
Electrical Properties
| Dielectric Strength (Breakdown Potential), kV/mm | 30 to 33 | |
| 0.5 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.3 to 1.5 | |
| 0.5 |
| Limiting Oxygen Index (LOI), % | 47 to 50 | |
| 24 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.5 to 2.1 | |
| 18 |
| Strength to Weight: Axial, points | 24 to 30 | |
| 47 |
| Strength to Weight: Bending, points | 40 to 44 | |
| 86 |
| Thermal Diffusivity, mm2/s | 0.11 to 0.14 | |
| 0.17 |
| Thermal Shock Resistance, points | 44 to 100 | |
| 58 |