Species data
Black Walnut
Juglans nigra - a hardwood . Also sold as american walnut, eastern black walnut.
Properties at a glance
| Janka hardness | 1,010 lbf |
| Stiffness (MOE) | 1,680,000 psi |
| Specific gravity | 0.61 |
| Density | 38.1 lb/ft3 (610 kg/m3) |
| Weight per board foot | 3.17 lb |
| Shrinkage, green to oven-dry | 7.8% tangential / 5.5% radial |
| Movement coefficient (CT / CR) | 0.00274 / 0.00190 |
| Indicative price | $12.00 per board foot (estimated) |
Values are at about 12% moisture content. Density is specific gravity times 62.4; a board foot is one twelfth of a cubic foot, so weight per board foot is that density divided by twelve. Anything marked estimated is our own figure, not a measured one.
How Black Walnut compares
Measured against the 113 solid woods in this database: it is harder than 50% of them, heavier than 50%, and stiffer than 55%.
What that means in the shop
A 4/4 board 8 inches wide and 8 feet long is 5.33 board feet, so in Black Walnut it weighs about 16.9 lb. A stack of ten is 169 lb - worth knowing before you load a rack or a car.
Against red oak, the trade's usual yardstick at 1,220 lbf, Black Walnut is about 83% as hard and 87% as heavy.
Its shrinkage is 7.8% tangential against 5.5% radial, a ratio of 1.4 to 1. The wider that ratio, the more unevenly a flatsawn board moves across its width as humidity changes, and the more it wants to cup; anything near or above 2 to 1 is worth quartersawing or restraining for panels and wide tops. This one moves comparatively evenly.
Woods of similar hardness
Closest to Black Walnut on hardness in this database: American Holly (1,020 lbf), Anigre (990 lbf), Imbuia (970 lbf), Black Cherry (950 lbf). Similar hardness does not mean similar behaviour - check density and movement before substituting one for another.
Related calculators
Sources
- The Wood Database - Black Walnut
- Dimensional change coefficient table (USDA FPL Wood Handbook, Table 13-5; values per Hoadley, Understanding Wood)
MOE, shrinkage, Janka, and SG from The Wood Database (which cites the USDA FPL Wood Handbook). CT/CR from USDA FPL Wood Handbook Table 13-5 (Walnut, black). Price indicative only.
These calculators are for planning and estimation. Engineering results (shelf sag, wood movement) use published average material properties; real boards vary by grade, grain, moisture and defects. Verify load-bearing designs with a professional.