Aspens & cottonwoods
Hardness among the 3 aspens & cottonwoods here ranges from 350 lbf (Quaking aspen) to 430 lbf (Eastern cottonwood). The flattest-drying is Quaking aspen; the stiffest is Eastern cottonwood.
- Its median hardness, 350 lbf, is 70% below the median for U.S. hardwoods.
- The hardest is only 1.23 times as hard as the softest, one of the three narrowest spreads among the 15 families here.
- Every one of the three has a T/R ratio above the median for all 155 woods (1.81), so flatsawn boards of this family tend to move unevenly.
- All three sit in the softest quarter of the 155 woods, at 565 lbf or less.
- 350 lbfmedian hardness
- 0.35median density
- 8,500 psimedian bending strength
- 8.6%median face shrinkage
Aspens & cottonwoodsOther woodsNorthern red oak, the usual yardstick
Ranked by hardness
Hardest first. Density is specific gravity; shrinkage is volumetric, green to oven-dry.
| # | Wood | Janka, lbf | Density | Bending, psi | Shrinkage |
|---|---|---|---|---|---|
| 1 | Eastern cottonwoodPopulus deltoidesSG 0.37 · 13.9% shrinkage | 430 | 0.37 | 8,500 | 13.9% |
| 2 | Black cottonwoodPopulus trichocarpaSG 0.31 · 12.4% shrinkage | 350 | 0.31 | 8,500 | 12.4% |
| 3 | Quaking aspenPopulus tremuloidesSG 0.35 · 11.5% shrinkage | 350 | 0.35 | 8,400 | 11.5% |
Source: USDA Forest Products Laboratory, Wood Handbook (2010), Tables 4-3, 4-4, 5-3b and 5-5b. How we use the data · Compare or filter these woods · Guide: Hardwood vs softwood in numbers