Spruce-pine-fir vs. PAR
Spruce-pine-fir belongs to the wood-based materials classification, while PAR belongs to the thermoplastics. There are 15 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 spruce-pine-fir and the bottom bar is PAR.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 50 | |
| 93 |
| Elastic (Young's, Tensile) Modulus, GPa | 16 | |
| 2.0 |
| Elongation at Break, % | 1.5 | |
| 50 |
| Tensile Strength: Ultimate (UTS), MPa | 85 | |
| 67 |
Thermal Properties
| Specific Heat Capacity, J/kg-K | 1380 | |
| 1200 |
| Thermal Conductivity, W/m-K | 0.12 | |
| 0.18 |
| Thermal Expansion, µm/m-K | 6.5 | |
| 88 |
Electrical Properties
| Dielectric Strength (Breakdown Potential), kV/mm | 0.5 | |
| 16 |
Otherwise Unclassified Properties
| Density, g/cm3 | 0.5 | |
| 1.2 |
| Limiting Oxygen Index (LOI), % | 24 | |
| 35 |
Common Calculations
| Stiffness to Weight: Axial, points | 18 | |
| 0.93 |
| Strength to Weight: Axial, points | 47 | |
| 16 |
| Strength to Weight: Bending, points | 86 | |
| 31 |
| Thermal Diffusivity, mm2/s | 0.17 | |
| 0.13 |
| Thermal Shock Resistance, points | 58 | |
| 27 |