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.

MachiningNailing Screwing GluingFinishing
ExcellentGoodGoodGoodExcellent

 

Strength and Mechanical Properties: (inch-pound)

Moisture ContentGreen-12%
Specific Gravity0.51-0.55
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