Obeche
Triplochiton scleroxylon
Obeche measures 430 lbf on the Janka scale, about 33% as hard as northern red oak.
- Only ceiba and northern white-cedar are lighter, only ceiba and northern white-cedar bend more easily, and only four woods are weaker in bending.
- It is harder than its weight suggests: across all 155 woods, a specific gravity of 0.30 goes with about 110 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
ObecheImported woods medianOther woods
Density
0.303rd lightest of 15551% below the imported woods median0.250.96Stiffness
0.86 M psi5.9 GPa3rd most flexible of 15557% below the imported woods median0.54 M psi4.06 M psiBending strength
7,400 psi51.0 MPa5th weakest of 15556% below the imported woods median4,300 psi29,900 psiShrinkage across the face
5.4%radial 3.0%15th lowest of 15532% below the imported woods median3.5%12.7%Janka hardness
430 lbf1,913 N18th softest of 15562nd of 65 imported woods; 67% below the imported woods median240 lbf3,680 lbfCupping tendency
1.8074th lowest of 1551.092.90
How much it moves
Its face shrinkage of 5.4% is in the lowest quarter of the list, with an ordinary T/R ratio of 1.80.
0.32 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.18 in.
- Tangential
- 5.4%
- Radial
- 3.0%
- Volume
- 9.2%
- T/R ratio
- 1.80 (74th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
Woods of similar hardness
The eight nearest on the Janka scale, lbf.
Laboratory values
Its most unusual laboratory figure is crushing strength along the grain: 2nd lowest of the 154 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Compression parallel to grain | 2,570psi | 3,930psi | +53% | 27.1MPa |
| Modulus of elasticity | 0.72M psi | 0.86M psi | +19% | 5.93GPa |
| Modulus of rupture | 5,100psi | 7,400psi | +45% | 51MPa |
| Side hardness | 420lbf | 430lbf | +2% | 1,913N |
| Shear parallel to grain | 660psi | 990psi | +50% | 6.80MPa |
| Work to maximum load | 6.20in-lbf/in³ | 6.90in-lbf/in³ | +11% | 47.6kJ/m³ |
Wood Handbook Table 5-5b, Table 4-4. Data & method · Guides