Black Walnut (Juglans nigra)
Description: The sapwood of walnut is creamy white, while the heartwood is light brown to dark chocolate brown, occasionally with a purplish cast and darker streaks. The wood develops a rich patina that grows more lustrous with age. Walnut is usually supplied steamed, to darken sapwood. The wood is generally straight-grained, but sometimes with wavy or curly grain that produces an attractive and decorative figure. This species produces a greater variety of figure types than any other.
Main Uses: Furniture, cabinets, architectural millwork, doors, flooring, paneling and gun stocks. A favored wood for using in contrast with lighter-colored species.
Physical Properties: Walnut is a tough hardwood of medium density, with moderate bending and crushing strengths and low stiffness. It has a good steam-bending classification.
Availability: Reasonable availability with regional limitations.
Working Properties: Walnut works easily with hand and machine tools, and nails, screws and glues well. It holds paint and stain very well for an exceptional finish and is readily polished. It dries slowly, and care is needed to avoid kiln degrade. Walnut has good dimensional stability.
Machining | Nailing | Screwing | Gluing | Finishing |
Excellent | Good | Good | Good | Excellent |
Strength and Mechanical Properties: (inch-pound)
Moisture Content | Green-12% |
Specific Gravity | 0.51-0.55 |
Static Bending: Modulus of Rupture (lbf/in^2) | 9,500-14,600 |
Static Bending: Modulus of Elasticity (10^6 lbf/in^2) | 1.42-1.68 |
Static Bending: Work to Maximum Load (in-lbf/in^3) | 10.7-14.6 |
Impact Bending to Grain (in) | 34-37 |
Compression Parallel to Grain (lbf/in^2) | 4,300-7,580 |
Compression Perpendicular to Grain (lbf/in^2) | 490-1,010 |
Shear Parallel to Grain (lbf/in^2) | 1,220-1,370 |
Tension Perpendicular to Grain (lbf/in^2) | 570-690 |
Side Hardness (lbf) | 900-1,010 |
Source: American Hardwood Information Center, Species Guide