Northern red oak
Quercus rubra
Northern red oak measures 1,290 lbf on the Janka scale and is the yardstick every other wood here is compared with.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Northern red oakU.S. hardwoods medianOther woods
Cupping tendency
2.1528th highest of 1551.092.90Janka hardness
1,290 lbf5,738 N51st hardest of 15518th of 53 U.S. hardwoods240 lbf3,680 lbfDensity
0.560.63 at 12% MC52nd heaviest of 1550.250.96Shrinkage across the face
8.6%radial 4.0%52nd highest of 1553.5%12.7%Stiffness
1.82 M psi12.6 GPa55th stiffest of 1550.54 M psi4.06 M psiBending strength
14,300 psi98.6 MPa60th strongest of 1554,300 psi29,900 psi
How much it moves
Most of its movement runs along the rings (T/R 2.15): quartersawn, the same board would lose 0.24 in. instead of 0.52 in.
0.52 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 8.6%
- Radial
- 4.0%
- Volume
- 13.7%
- T/R ratio
- 2.15 (127th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Pin oak
17% harder · 4% heavier · shrinks 0.9 points more across the face
- Red maple
26% softer · 12% lighter · shrinks 0.4 points less across the face
- Laurel oak
6% softer · same density · shrinks 1.3 points more across the face
Among the oaks
8th 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 |
|---|---|---|---|---|
| Tension perpendicular | 750psi | 800psi | +7% | 5.50MPa |
| Impact bending | 44in. | 43in. | −2% | 1,092mm |
| Compression perpendicular | 610psi | 1,010psi | +66% | 7.00MPa |
| Work to maximum load | 13.2in-lbf/in³ | 14.5in-lbf/in³ | +10% | 100kJ/m³ |
| Side hardness | 1,000lbf | 1,290lbf | +29% | 5,738N |
| Modulus of elasticity | 1.35M psi | 1.82M psi | +35% | 12.6GPa |
| Modulus of rupture | 8,300psi | 14,300psi | +72% | 98.6MPa |
| Shear parallel to grain | 1,210psi | 1,780psi | +47% | 12.3MPa |
| Compression parallel to grain | 3,440psi | 6,760psi | +97% | 46.6MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides