Field data
  • Janka hardness 430 lbfred oak ≈ 1,290 lbf
  • Density ≈ 27 lb/ft³specific gravity 0.39 at 12% MC
  • Shrinkage — tangential 8.7%flatsawn width, green → ovendry
  • Shrinkage — radial 3.3%quartersawn width
  • T/R ratio 2.6 : 1higher = more cupping in flatsawn stock

Shop notes Light and shock-absorbent — once artificial-limb stock. Fuzzy to machine; better carved or turned than joined.

Seasonal movement at a glance

Width change for black willow across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:

Board widthFlatsawnQuartersawn
6″ 1/8″ (0.112″) 1/32″ (0.042″)
12″ 7/32″ (0.224″) 3/32″ (0.085″)
24″ 7/16″ (0.447″) 5/32″ (0.170″)
36″ 21/32″ (0.671″) 1/4″ (0.255″)

Run your own numbers

Different width, different climate swing — the calculator below is preset to black willow:

Board & conditions
Grain
Conditions given as

Typical swings:

Black Willow questions

How much does black willow move with the seasons?

A 12″-wide flatsawn black willow board moves about 7/32″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 3/32″. Its tangential shrinkage is 8.7% and radial 3.3% (green to ovendry) — a moderate-movement wood.

How hard is black willow?

Black Willow rates about 430 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 27 lb/ft³ at indoor moisture levels.

Is black willow good for wide panels and tabletops?

Carefully. Its tangential-to-radial ratio of 2.6:1 makes flatsawn boards prone to cupping — choose quartersawn stock for wide glue-ups, alternate growth rings, and fasten tops so they can slide.

Similar species

Eastern Cottonwood · Bigtooth Aspen · American Basswood · Butternut · Quaking Aspen · American Chestnut

Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.