How to Identify Black Walnut Wood (Juglans nigra)

Heartwood ranges from a lighter pale brown to a dark chocolate brown with darker brown streaks. Grain usually straight but can be irregular; medium texture with moderate natural luster. End grain: Semi-ring-porous (sometimes closer to diffuse porous); vessels large to very large in earlywood grading to medium in latewood, few to very few, tyloses common; parenchyma diffuse-in-aggregates and banded; rays narrow to medium, generally not visible without magnification.

Janka hardness 1,010 lbf (side hardness: the force needed to embed a 0.444-inch steel ball to half its diameter). Specific gravity 0.55 at 12% moisture content, so a cubic foot weighs roughly 34 lb. Weight in the hand is one of the quickest checks: compare a piece of known size against a board you already know.

Yellow-poplar and other pale, inexpensive hardwoods are sometimes stained dark to mimic walnut's color; genuine walnut shows real dark-brown heartwood streaks running with the grain and a much higher density/hardness (1,010 lbf vs. poplar's 540 lbf) and medium (not fine/light) texture, whereas dyed color sits only on the surface and the underlying wood is lighter and softer. The Yellow Poplar (Tulip Poplar) page has its own details.

Faint, mild odor when being worked, which helps distinguish it from unrelated walnut lookalikes; reported as a sensitizer causing eye and skin irritation.

Furniture, cabinetry, gunstocks, interior paneling, veneer, turned items, and other small wooden objects and novelties.

Typically easy to work provided the grain is straight and regular; planer tearout may occur with irregular grain; glues, stains, and finishes well (though rarely stained); reported as a sensitizer causing eye and skin irritation.

Photograph a freshly cut or sanded face in daylight, not a finished or stained surface, since stain hides color and finish flattens grain. Add a close-up of the end grain: cut a clean end, wet it or sand it to 220, and shoot from straight on; pore pattern and rays are the most reliable marks. Put a ruler in frame. The app suggests the likely species; confirm with the end grain and weight.