Field data
  • Janka hardness 1,060 lbfred oak ≈ 1,290 lbf
  • Density ≈ 41 lb/ft³specific gravity 0.59 at 12% MC
  • Shrinkage — tangential 11.3%flatsawn width, green → ovendry
  • Shrinkage — radial 4.7%quartersawn width
  • T/R ratio 2.4 : 1higher = more cupping in flatsawn stock

Shop notes Coarser and faster-grown than northern red oak, with one of the widest movement spreads of any oak. Acclimate it longer than you think.

Seasonal movement at a glance

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

Board widthFlatsawnQuartersawn
6″ 5/32″ (0.145″) 1/16″ (0.060″)
12″ 9/32″ (0.291″) 1/8″ (0.121″)
24″ 19/32″ (0.581″) 1/4″ (0.242″)
36″ 7/8″ (0.872″) 3/8″ (0.363″)

Run your own numbers

Different width, different climate swing — the calculator below is preset to southern red oak:

Board & conditions
Grain
Conditions given as

Typical swings:

Southern Red Oak questions

How much does southern red oak move with the seasons?

A 12″-wide flatsawn southern red oak board moves about 9/32″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 11.3% and radial 4.7% (green to ovendry) — a high-movement wood.

How hard is southern red oak?

Southern Red Oak rates about 1,060 lbf on the Janka scale — softer than red oak but sturdy (red oak is roughly 1,290 lbf). Density runs about 41 lb/ft³ at indoor moisture levels.

Is southern red oak good for wide panels and tabletops?

Carefully. Its tangential-to-radial ratio of 2.4:1 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

African Mahogany (Khaya) · Teak · Southern Magnolia · American Holly · Black Walnut · 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.