American Elm
Ulmus americana · hardwood · Eastern North America · high movement
- Janka hardness 830 lbfred oak ≈ 1,290 lbf
- Density ≈ 35 lb/ft³specific gravity 0.5 at 12% MC
- Shrinkage — tangential 9.5%flatsawn width, green → ovendry
- Shrinkage — radial 4.2%quartersawn width
- T/R ratio 2.3 : 1higher = more cupping in flatsawn stock
Shop notes Interlocked grain that refuses to split — the traditional chair-seat wood. That same grain tears out when planing; favor sharp, light cuts and expect lively movement.
Seasonal movement at a glance
Width change for american elm across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 1/8″ (0.122″) | 1/16″ (0.054″) |
| 12″ | 1/4″ (0.244″) | 3/32″ (0.108″) |
| 24″ | 1/2″ (0.489″) | 7/32″ (0.216″) |
| 36″ | 23/32″ (0.733″) | 5/16″ (0.324″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to american elm:
Typical swings:
American Elm questions
How much does american elm move with the seasons?
A 12″-wide flatsawn american elm board moves about 1/4″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 3/32″. Its tangential shrinkage is 9.5% and radial 4.2% (green to ovendry) — a high-movement wood.
How hard is american elm?
American Elm rates about 830 lbf on the Janka scale — softer than red oak but sturdy (red oak is roughly 1,290 lbf). Density runs about 35 lb/ft³ at indoor moisture levels.
Is american elm good for wide panels and tabletops?
Carefully. Its tangential-to-radial ratio of 2.3:1 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
Black Ash · Bigleaf Maple · Sweetgum · Black Tupelo (Blackgum) · Slippery Elm · Honduran Mahogany
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.