Black Walnut
Juglans nigra · hardwood · Eastern North America · moderate movement
- Janka hardness 1,010 lbfred oak ≈ 1,290 lbf
- Density ≈ 38 lb/ft³specific gravity 0.55 at 12% MC
- Shrinkage — tangential 7.8%flatsawn width, green → ovendry
- Shrinkage — radial 5.5%quartersawn width
- T/R ratio 1.4 : 1higher = more cupping in flatsawn stock
Shop notes The American furniture aristocrat — chocolate heartwood, cream sapwood, and manners to match: machines crisply, glues well, and moves moderately with a forgiving 1.4:1 spread. This site’s palette is sampled from one board of it.
Seasonal movement at a glance
Width change for black walnut across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 3/32″ (0.100″) | 1/16″ (0.071″) |
| 12″ | 3/16″ (0.201″) | 5/32″ (0.141″) |
| 24″ | 13/32″ (0.401″) | 9/32″ (0.283″) |
| 36″ | 19/32″ (0.602″) | 7/16″ (0.424″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to black walnut:
Typical swings:
Black Walnut questions
How much does black walnut move with the seasons?
A 12″-wide flatsawn black walnut board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 5/32″. Its tangential shrinkage is 7.8% and radial 5.5% (green to ovendry) — a moderate-movement wood.
How hard is black walnut?
Black Walnut rates about 1,010 lbf on the Janka scale — softer than red oak but sturdy (red oak is roughly 1,290 lbf). Density runs about 38 lb/ft³ at indoor moisture levels.
Is black walnut good for wide panels and tabletops?
Yes, with normal precautions: its 1.4:1 tangential-to-radial ratio is unusually balanced, so panels stay flatter than most. Still fasten solid tops so they can move across their width.
Similar species
Southern Magnolia · American Holly · Southern Red Oak · Black Cherry · Red Maple · African Mahogany (Khaya)
Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.