Subalpine fir
Abies lasiocarpa
Subalpine fir measures 350 lbf on the Janka scale, about 27% as hard as northern red oak.
- Only eastern white pine has a higher T/R ratio, and only ceiba and northern white-cedar are softer, and only ceiba, northern white-cedar and obeche are lighter.
- Of the seven true firs in the handbook, none bends more easily.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Subalpine firU.S. softwoods medianOther woods
Cupping tendency
2.852nd highest of 15553% above the U.S. softwoods median1.092.90Janka hardness
350 lbf1,557 N3rd softest of 15534th of 37 U.S. softwoods; 30% below the U.S. softwoods median240 lbf3,680 lbfDensity
0.310.32 at 12% MC4th lightest of 1550.250.96Bending strength
8,600 psi59.3 MPa15th weakest of 1554,300 psi29,900 psiStiffness
1.29 M psi8.9 GPa26th most flexible of 1550.54 M psi4.06 M psiShrinkage across the face
7.4%radial 2.6%59th lowest of 1553.5%12.7%
For its weight: stiffness-to-weight 4.16 (19th of 155).
How much it moves
Most of its movement runs along the rings (T/R 2.85): quartersawn, the same board would lose 0.16 in. instead of 0.44 in.
0.44 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 7.4%
- Radial
- 2.6%
- Volume
- 9.4%
- T/R ratio
- 2.85 (154th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Balsam fir
9% harder · 6% heavier · shrinks 0.5 points less across the face
- Eastern white pine
9% harder · 10% heavier · shrinks 1.3 points less across the face
- Eastern hemlock
43% harder · 23% heavier · shrinks 0.6 points less across the face
Among the true firs
7th hardest of 7, lbf.
Laboratory values
Its most unusual laboratory figure is crushing strength across the grain: 6th lowest of the 90 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Side hardness | 260lbf | 350lbf | +35% | 1,557N |
| Compression perpendicular | 190psi | 390psi | +105% | 2.70MPa |
| Modulus of rupture | 4,900psi | 8,600psi | +76% | 59.3MPa |
| Compression parallel to grain | 2,300psi | 4,860psi | +111% | 33.5MPa |
| Modulus of elasticity | 1.05M psi | 1.29M psi | +23% | 8.89GPa |
| Shear parallel to grain | 700psi | 1,070psi | +53% | 7.40MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides