Tropical oak (roble)
Quercus spp.
Tropical oak (roble) measures 2,500 lbf on the Janka scale, 94% harder than northern red oak.
- Of the 155 woods, only four shrink more across the face, six lose more volume on drying and seven are stiffer.
- Of the 15 oaks in the handbook, none is harder or heavier.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Tropical oak (roble)Imported woods medianOther woods
Shrinkage across the face
11.7%radial 6.4%5th highest of 15548% above the imported woods median3.5%12.7%Stiffness
3.02 M psi20.8 GPa8th stiffest of 15551% above the imported woods median0.54 M psi4.06 M psiBending strength
23,000 psi158.6 MPa9th strongest of 15538% above the imported woods median4,300 psi29,900 psiJanka hardness
2,500 lbf11,121 N11th hardest of 15511th of 65 imported woods; 92% above the imported woods median240 lbf3,680 lbfDensity
0.7614th heaviest of 1550.250.96Cupping tendency
1.8374th highest of 1551.092.90
For its weight: strength-to-weight 30,263 psi (14th of 155).
How much it moves
Its face shrinkage of 11.7% is in the top quarter of the list, with an ordinary T/R ratio of 1.83.
0.70 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.38 in.
- Tangential
- 11.7%
- Radial
- 6.4%
- Volume
- 18.5%
- T/R ratio
- 1.83 (81st most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Mora
8% softer · 3% heavier · shrinks 1.9 points less across the face
- Manbarklak
39% harder · 14% heavier · shrinks 1.4 points less across the face
- Karri
18% softer · 8% heavier · shrinks 0.7 points more across the face
Among the oaks
1st 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 stiffness (modulus of elasticity): 8th highest of the 155 woods with a published value.
| Property | Dry, 12% MC | Metric, 12% MC |
|---|---|---|
| Modulus of elasticity | 3.02M psi | 20.8GPa |
| Modulus of rupture | 23,000psi | 158.6MPa |
| Side hardness | 2,500lbf | 11,121N |
| Work to maximum load | 16.5in-lbf/in³ | 113.8kJ/m³ |
The handbook publishes only values at 12% moisture content for this wood; green values and some tests are not given.
Wood Handbook Table 5-5b, Table 4-4. Data & method · Guides