WOOD SPECIES · Hardwood
Black walnut: density, weight and properties
Juglans nigra
Black walnut (Juglans nigra) averages 616 kg/m³ at 12% moisture content, according to the USDA Wood Handbook. The figures below are averages for clear, mature wood; individual boards vary with origin, growth and moisture.
Key figures
- Density at 12% moisture
- 616 kg/m³Specific gravity 0.55 (oven-dry mass, volume at 12%) × 1.12 × 1,000 kg/m³, Wood Handbook Eq. 4-14
- Basic specific gravity (oven-dry mass, green volume)
- 0.51
- Janka side hardness at 12%
- 4,500 N (≈ 1,012 lbf)
- Bending strength (modulus of rupture)
- 101 MPa
- Stiffness (modulus of elasticity)
- 11,600 MPa
- Compression parallel to grain
- 52.3 MPa
- Tangential shrinkage, green to oven-dry
- 7.8%
- Radial shrinkage, green to oven-dry
- 5.5%
- Volumetric shrinkage, green to oven-dry
- 12.8%
- Fibre saturation point
- 30%Not measured: Wood Handbook default
Weight at 12% moisture content
Volume × 616 kg/m³, the same calculation as the weight calculator. Green or wet wood weighs considerably more.
| Piece | Size | Weight |
|---|---|---|
| 1 cubic metre | 1,000 × 1,000 × 1,000 mm | 616 kg |
| 1 board foot | 12 × 12 × 1 in | 1.45 kg |
| 1×4 board, 8 ft | 3/4 × 3 1/2 in actual × 8 ft | 2.54 kg |
| 1×6 board, 8 ft | 3/4 × 5 1/2 in actual × 8 ft | 4 kg |
| 2×4 board, 8 ft | 1 1/2 × 3 1/2 in actual × 8 ft | 5.09 kg |
| 2×6 board, 10 ft | 1 1/2 × 5 1/2 in actual × 10 ft | 9.99 kg |
Movement across the width
How much a board 11 1/4 in (286 mm) wide changes when its moisture content moves by a few percentage points. The estimate uses the total shrinkage above and a linear relation below the fibre saturation point of 30% (Wood Handbook Eq. 4-9). Flat-sawn boards move with tangential shrinkage, quartersawn boards with radial shrinkage.
| Moisture change | Flat-sawn | Quartersawn |
|---|---|---|
| 3 percentage points | 2.2 mm (0.088 in) | 1.6 mm (0.062 in) |
| 6 percentage points | 4.5 mm (0.176 in) | 3.1 mm (0.124 in) |
Wood movement across the grain · Moisture content and acclimatising wood
Natural durability
The Wood Handbook groups the heartwood as resistant to decay (Table 14-1). Resistant heartwood generally gives satisfactory service above ground where decay can occur; ground contact calls for very resistant or treated wood.
Working and finishing
Normally straight grained, easily worked with tools and stable in use; heavy, hard, strong and stiff with good shock resistance. The Wood Handbook describes black walnut as well suited to natural finishes.
The Wood Handbook names oak, ash, hickory and walnut among the hardwoods with large vessels: for a smooth film finish the pores may need a filler, followed by light sanding.
Typical uses
- Furniture
- Interior joinery and millwork
- Panelling
- Cabinets
Calculate with this material
Species with similar density
- Tauari 620 kg/m³
- Eucalyptus grandis 600 kg/m³
- European larch 600 kg/m³
Sources & references
- USDA FPL · Wood Handbook (2021), ch. 5: Mechanical properties of wood
- USDA FPL · Wood Handbook (2021), ch. 4: Moisture relations and physical properties of wood
- USDA FPL · Wood Handbook (2021), ch. 14: Biodeterioration of wood
- USDA FPL · Wood Handbook (2021), ch. 2: Characteristics and availability of commercially important woods
- USDA FPL · Wood Handbook (2021), ch. 16: Finishing of wood
Uses and working notes summarise the cited source. Check the moisture content, grade and origin of the wood you actually buy.