Black walnut
Juglans nigra
Black walnut measures 1,010 lbf on the Janka scale, 22% softer than northern red oak.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Black walnutU.S. hardwoods medianOther woods
Cupping tendency
1.4215th lowest of 1551.092.90Bending strength
14,600 psi100.7 MPa55th strongest of 1554,300 psi29,900 psiJanka hardness
1,010 lbf4,493 N74th hardest of 15531st of 53 U.S. hardwoods240 lbf3,680 lbfStiffness
1.68 M psi11.6 GPa74th stiffest of 1550.54 M psi4.06 M psiDensity
0.510.55 at 12% MC75th heaviest of 1550.250.96Shrinkage across the face
7.8%radial 5.5%76th highest of 1553.5%12.7%
How much it moves
The two directions move almost alike (T/R 1.42), so flatsawn and quartersawn boards differ by only 0.14 in.
0.47 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 7.8%
- Radial
- 5.5%
- Volume
- 12.8%
- T/R ratio
- 1.42 (15th most stable of 155)
End view, shrinkage drawn 3× life size.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Compression perpendicular | 490psi | 1,010psi | +106% | 7.00MPa |
| Tension perpendicular | 570psi | 690psi | +21% | 4.80MPa |
| Impact bending | 37in. | 34in. | −8% | 864mm |
| Modulus of rupture | 9,500psi | 14,600psi | +54% | 100.7MPa |
| Compression parallel to grain | 4,300psi | 7,580psi | +76% | 52.3MPa |
| Shear parallel to grain | 1,220psi | 1,370psi | +12% | 9.40MPa |
| Work to maximum load | 14.6in-lbf/in³ | 10.7in-lbf/in³ | −27% | 73.8kJ/m³ |
| Modulus of elasticity | 1.42M psi | 1.68M psi | +18% | 11.6GPa |
| Side hardness | 900lbf | 1,010lbf | +12% | 4,493N |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides