hardwood · Robinia pseudoacacia

Black Locust wood properties

Also known as: robinia, false acacia.

Type hardwood
Botanical name Robinia pseudoacacia
Modulus of elasticity (MOE) 2,050,000 psi
Specific gravity 0.77
Density (approx) 48 lb/ft³ (4.0 lb per board foot)
Janka hardness 1,700 lbf
Shrinkage (tangential / radial) 7.2% / 4.6%
Region Central and eastern United States

A 1 in x 6 in x 8 ft board of Black Locust weighs about 16.0 lb (roughly 48 lb per cubic foot). Its Janka hardness of 1,700 lbf is harder than about 73% of the woods in our database.

Uses and working notes

Common uses: fence posts, flooring, furniture, boatbuilding, turned objects, veneer.

Durability: Very durable and weathers well; long favored for fence posts left outdoors.

Workability: Dense and hard, machining proves tough and edges dull moderately; steam-bends and turns superbly; finishes and glues well.

Use this data

Similar woods

Woods with comparable hardness and density to Black Locust:

How these numbers were sourced

MOE, SG (12% MC), Janka and shrinkage from The Wood Database (cites USDA FPL Wood Handbook). Uses, region, durability and workability summarized from The Wood Database. Black Locust is not listed in the FPL/Hoadley dimensional change coefficient table (Popular Woodworking reproduction), so CT/CR are omitted. Price indicative.

Values shown as estimates rather than sourced constants: typicalPricePerBF_usd.

Sources

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.