Willow oak
Quercus phellos
Willow oak measures 1,460 lbf on the Janka scale, 13% harder than northern red oak.
- Only karri, shellbark hickory and laurel oak lose more volume on drying.
- Across all 155 woods it falls in the top fifth for face shrinkage.
- On the Janka scale its nearest neighbours are sugar maple at 1,450 lbf and sweet birch at 1,470 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Willow oakU.S. hardwoods medianOther woods
Shrinkage across the face
9.6%radial 5.0%30th highest of 1553.5%12.7%Janka hardness
1,460 lbf6,494 N40th hardest of 1559th of 53 U.S. hardwoods; 26% above the U.S. hardwoods median240 lbf3,680 lbfStiffness
1.90 M psi13.1 GPa47th stiffest of 1550.54 M psi4.06 M psiDensity
0.560.69 at 12% MC52nd heaviest of 1550.250.96Cupping tendency
1.9255th highest of 1551.092.90Bending strength
14,500 psi100.0 MPa57th strongest of 1554,300 psi29,900 psi
How much it moves
Its face shrinkage of 9.6% is in the top quarter of the list, with an ordinary T/R ratio of 1.92.
0.58 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.30 in.
- Tangential
- 9.6%
- Radial
- 5.0%
- Volume
- 18.9%
- T/R ratio
- 1.92 (98th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Sugar maple
1% softer · same density · shrinks 0.3 points more across the face
- Water oak
18% softer · same density · shrinks 0.2 points more across the face
- Pin oak
3% harder · 4% heavier · shrinks 0.1 points less across the face
Among the oaks
3rd hardest of 15, lbf; the neighbours either side are shown, the rest are on the oaks page.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Compression perpendicular | 610psi | 1,130psi | +85% | 7.80MPa |
| Impact bending | 35in. | 42in. | +20% | 1,067mm |
| Side hardness | 980lbf | 1,460lbf | +49% | 6,494N |
| Work to maximum load | 8.80in-lbf/in³ | 14.6in-lbf/in³ | +66% | 100.7kJ/m³ |
| Modulus of elasticity | 1.29M psi | 1.90M psi | +47% | 13.1GPa |
| Modulus of rupture | 7,400psi | 14,500psi | +96% | 100MPa |
| Shear parallel to grain | 1,180psi | 1,650psi | +40% | 11.4MPa |
| Compression parallel to grain | 3,000psi | 7,040psi | +135% | 48.5MPa |
| Tension perpendicular | 760psi | not tested | — | — |
Note on the data: the published volumetric shrinkage is unusually high relative to radial + tangential shrinkage.
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides