Black Ash
Fraxinus nigra · hardwood · Eastern North America · moderate movement
- Janka hardness 850 lbfred oak ≈ 1,290 lbf
- Density ≈ 34 lb/ft³specific gravity 0.49 at 12% MC
- Shrinkage — tangential 7.8%flatsawn width, green → ovendry
- Shrinkage — radial 5%quartersawn width
- T/R ratio 1.6 : 1higher = more cupping in flatsawn stock
Shop notes Softer and lighter than white ash; the traditional basket-splint wood. Works easily but dents more readily.
Seasonal movement at a glance
Width change for black ash across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 3/32″ (0.100″) | 1/16″ (0.064″) |
| 12″ | 3/16″ (0.201″) | 1/8″ (0.129″) |
| 24″ | 13/32″ (0.401″) | 1/4″ (0.257″) |
| 36″ | 19/32″ (0.602″) | 3/8″ (0.386″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to black ash:
Typical swings:
Black Ash questions
How much does black ash move with the seasons?
A 12″-wide flatsawn black ash board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 7.8% and radial 5% (green to ovendry) — a moderate-movement wood.
How hard is black ash?
Black Ash rates about 850 lbf on the Janka scale — softer than red oak but sturdy (red oak is roughly 1,290 lbf). Density runs about 34 lb/ft³ at indoor moisture levels.
Is black ash good for wide panels and tabletops?
Yes, with normal precautions: its 1.6:1 tangential-to-radial ratio is unusually balanced, so panels stay flatter than most. Still fasten solid tops so they can move across their width.
Similar species
Bigleaf Maple · Sweetgum · Slippery Elm · American Elm · Hackberry · Water Tupelo
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.