Field data
  • Janka hardness 1,200 lbfred oak ≈ 1,290 lbf
  • Density ≈ 39 lb/ft³specific gravity 0.56 at 12% MC
  • Shrinkage — tangential 7.1%flatsawn width, green → ovendry
  • Shrinkage — radial 4.6%quartersawn width
  • T/R ratio 1.5 : 1higher = more cupping in flatsawn stock

Shop notes Sold interchangeably with white ash in most lumberyards; slightly lighter, with the same open grain and honest working manners.

Seasonal movement at a glance

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

Board widthFlatsawnQuartersawn
6″ 3/32″ (0.091″) 1/16″ (0.059″)
12″ 3/16″ (0.183″) 1/8″ (0.118″)
24″ 3/8″ (0.365″) 1/4″ (0.237″)
36″ 9/16″ (0.548″) 11/32″ (0.355″)

Run your own numbers

Different width, different climate swing — the calculator below is preset to green ash:

Board & conditions
Grain
Conditions given as

Typical swings:

Green Ash questions

How much does green ash move with the seasons?

A 12″-wide flatsawn green 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 7.1% and radial 4.6% (green to ovendry) — a moderate-movement wood.

How hard is green ash?

Green Ash rates about 1,200 lbf on the Janka scale — in red oak’s hardness neighborhood (red oak is roughly 1,290 lbf). Density runs about 39 lb/ft³ at indoor moisture levels.

Is green ash good for wide panels and tabletops?

Yes, with normal precautions: its 1.5:1 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

Black Oak · Black Maple · Oregon Ash · Yellow Birch · Iroko · Chestnut Oak

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.