Overcup oak
Quercus lyrata
Overcup oak measures 1,190 lbf on the Janka scale, 8% softer than northern red oak.
- No other wood in the tables shrinks more across the face.
- Only six of the 155 woods have a higher T/R ratio.
- Water oak has exactly the same Janka figure.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Overcup oakU.S. hardwoods medianOther woods
Shrinkage across the face
12.7%radial 5.3%1st highest of 15543% above the U.S. hardwoods median3.5%12.7%Cupping tendency
2.407th highest of 15528% above the U.S. hardwoods median1.092.90Stiffness
1.42 M psi9.8 GPa39th most flexible of 1550.54 M psi4.06 M psiDensity
0.570.63 at 12% MC49th heaviest of 1550.250.96Janka hardness
1,190 lbf5,293 N63rd hardest of 15524th of 53 U.S. hardwoods240 lbf3,680 lbfBending strength
12,600 psi86.9 MPa70th weakest of 1554,300 psi29,900 psi
For its weight: stiffness-to-weight 2.49 (149th of 155); strength-to-weight 22,105 psi (141st of 155).
How much it moves
Most of its movement runs along the rings (T/R 2.40): quartersawn, the same board would lose 0.32 in. instead of 0.76 in.
0.76 in.
off a 6-inch flatsawn board, green to oven-dry
- Tangential
- 12.7%
- Radial
- 5.3%
- Volume
- 16.0%
- T/R ratio
- 2.40 (147th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- American beech
9% harder · 2% lighter · shrinks 0.8 points less across the face
- Southern red oak
11% softer · 9% lighter · shrinks 1.4 points less across the face
- Chestnut oak
5% softer · same density · shrinks 1.9 points less across the face
Among the oaks
12th hardest of 15, lbf; the neighbours either side are shown, the rest are on the oaks page.
Laboratory values
Its most unusual laboratory figure is tension across the grain: 4th highest of the 73 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Tension perpendicular | 730psi | 940psi | +29% | 6.50MPa |
| Work to maximum load | 12.6in-lbf/in³ | 15.7in-lbf/in³ | +25% | 108.2kJ/m³ |
| Shear parallel to grain | 1,320psi | 2,000psi | +52% | 13.8MPa |
| Modulus of elasticity | 1.15M psi | 1.42M psi | +23% | 9.79GPa |
| Impact bending | 44in. | 38in. | −14% | 965mm |
| Compression parallel to grain | 3,370psi | 6,200psi | +84% | 42.7MPa |
| Side hardness | 960lbf | 1,190lbf | +24% | 5,293N |
| Compression perpendicular | 540psi | 810psi | +50% | 5.60MPa |
| Modulus of rupture | 8,000psi | 12,600psi | +57% | 86.9MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides