Southern red oak
Quercus falcata
Southern red oak measures 1,060 lbf on the Janka scale, 18% softer than northern red oak.
- Of the 155 woods, only six have a higher T/R ratio and eight shrink more across the face.
- Of the 15 oaks in the handbook, none is softer or lighter.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Southern red oakU.S. hardwoods medianOther woods
Cupping tendency
2.407th highest of 15528% above the U.S. hardwoods median1.092.90Shrinkage across the face
11.3%radial 4.7%9th highest of 15527% above the U.S. hardwoods median3.5%12.7%Stiffness
1.49 M psi10.3 GPa48th most flexible of 1550.54 M psi4.06 M psiBending strength
10,900 psi75.2 MPa49th weakest of 1554,300 psi29,900 psiDensity
0.520.59 at 12% MC69th heaviest of 1550.250.96Janka hardness
1,060 lbf4,715 N71st hardest of 15529th of 53 U.S. hardwoods240 lbf3,680 lbf
For its weight: strength-to-weight 20,962 psi (147th of 155).
How much it moves
Most of its movement runs along the rings (T/R 2.40): quartersawn, the same board would lose 0.28 in. instead of 0.68 in.
0.68 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 11.3%
- Radial
- 4.7%
- Volume
- 16.1%
- T/R ratio
- 2.40 (147th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Black oak
14% harder · 8% heavier · shrinks 0.2 points less across the face
- Chestnut oak
7% harder · 10% heavier · shrinks 0.5 points less across the face
- Sweetgum
20% softer · 12% lighter · shrinks 1.1 points less across the face
Among the oaks
15th hardest of 15, lbf; the neighbours either side are shown, the rest are on the oaks page.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Modulus of elasticity | 1.14M psi | 1.49M psi | +31% | 10.3GPa |
| Modulus of rupture | 6,900psi | 10,900psi | +58% | 75.2MPa |
| Work to maximum load | 8.00in-lbf/in³ | 9.40in-lbf/in³ | +18% | 64.8kJ/m³ |
| Compression parallel to grain | 3,030psi | 6,090psi | +101% | 42MPa |
| Compression perpendicular | 550psi | 870psi | +58% | 6.00MPa |
| Impact bending | 29in. | 26in. | −10% | 660mm |
| Shear parallel to grain | 930psi | 1,390psi | +49% | 9.60MPa |
| Side hardness | 860lbf | 1,060lbf | +23% | 4,715N |
| Tension perpendicular | 480psi | 510psi | +6% | 3.50MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides