Douglas-fir (Interior West)
Pseudotsuga menziesii
Douglas-fir (Interior West) measures 660 lbf on the Janka scale, 49% softer than northern red oak.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Douglas-fir (Interior West)U.S. softwoods medianOther woods
Cupping tendency
1.5631st lowest of 1551.092.90Janka hardness
660 lbf2,936 N49th softest of 1558th of 37 U.S. softwoods; 32% above the U.S. softwoods median240 lbf3,680 lbfStiffness
1.83 M psi12.6 GPa53rd stiffest of 1550.54 M psi4.06 M psiDensity
0.460.50 at 12% MC58th lightest of 1550.250.96Shrinkage across the face
7.5%radial 4.8%65th lowest of 1553.5%12.7%Bending strength
12,600 psi86.9 MPa70th weakest of 1554,300 psi29,900 psi
How much it moves
The two directions move almost alike (T/R 1.56), so flatsawn and quartersawn boards differ by only 0.16 in.
0.45 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 7.5%
- Radial
- 4.8%
- Volume
- 11.8%
- T/R ratio
- 1.56 (31st most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Loblolly pine
4% harder · 2% heavier · shrinks 0.1 points less across the face
- Douglas-fir (Coast)
8% harder · 2% lighter · shrinks 0.1 points more across the face
- Shortleaf pine
4% harder · 2% heavier · shrinks 0.2 points more across the face
Among the Douglas-fir growth regions
2nd hardest of 3, lbf.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Tension perpendicular | 290psi | 350psi | +21% | 2.40MPa |
| Side hardness | 510lbf | 660lbf | +29% | 2,936N |
| Shear parallel to grain | 940psi | 1,290psi | +37% | 8.90MPa |
| Modulus of elasticity | 1.51M psi | 1.83M psi | +21% | 12.6GPa |
| Compression parallel to grain | 3,870psi | 7,430psi | +92% | 51.2MPa |
| Impact bending | 26in. | 32in. | +23% | 813mm |
| Modulus of rupture | 7,700psi | 12,600psi | +64% | 86.9MPa |
| Work to maximum load | 7.20in-lbf/in³ | 10.6in-lbf/in³ | +47% | 73.1kJ/m³ |
| Compression perpendicular | 420psi | 760psi | +81% | 5.20MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides