Post Oak
Quercus stellata · hardwood · Southeastern US · high movement
- Janka hardness 1,360 lbfred oak ≈ 1,290 lbf
- Density ≈ 47 lb/ft³specific gravity 0.67 at 12% MC
- Shrinkage — tangential 9.8%flatsawn width, green → ovendry
- Shrinkage — radial 5.4%quartersawn width
- T/R ratio 1.8 : 1higher = more cupping in flatsawn stock
Shop notes The fence-post and barbecue oak — white oak group, dense and durable. Shop behavior mirrors white oak.
Seasonal movement at a glance
Width change for post oak 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″ (0.126″) | 1/16″ (0.069″) |
| 12″ | 1/4″ (0.252″) | 1/8″ (0.139″) |
| 24″ | 1/2″ (0.504″) | 9/32″ (0.278″) |
| 36″ | 3/4″ (0.756″) | 13/32″ (0.417″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to post oak:
Typical swings:
Post Oak questions
How much does post oak move with the seasons?
A 12″-wide flatsawn post oak board moves about 1/4″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 9.8% and radial 5.4% (green to ovendry) — a high-movement wood.
How hard is post oak?
Post Oak rates about 1,360 lbf on the Janka scale — in red oak’s hardness neighborhood (red oak is roughly 1,290 lbf). Density runs about 47 lb/ft³ at indoor moisture levels.
Is post oak good for wide panels and tabletops?
Yes, with normal precautions: its 1.8:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.
Similar species
White Oak · Bur Oak · White Ash · Rock Elm · Scarlet Oak · Sapele
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.