Opepe
Nauclea diderrichii
Opepe measures 1,630 lbf on the Janka scale, 26% harder than northern red oak.
- Drying barely changes its hardness: from 1,520 lbf green, it gains only 7% by 12% moisture, against a median of 31%.
- On the Janka scale its nearest neighbours are peroba de campos at 1,600 lbf and black locust at 1,700 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
OpepeImported woods medianOther woods
Bending strength
17,400 psi120.0 MPa32nd strongest of 1554,300 psi29,900 psiJanka hardness
1,630 lbf7,251 N33rd hardest of 15528th of 65 imported woods; 25% above the imported woods median240 lbf3,680 lbfDensity
0.6334th heaviest of 1550.250.96Stiffness
1.94 M psi13.4 GPa44th stiffest of 1550.54 M psi4.06 M psiShrinkage across the face
8.4%radial 4.5%59th highest of 1553.5%12.7%Cupping tendency
1.8768th highest of 1551.092.90
How much it moves
Both its face shrinkage (8.4%) and its T/R ratio (1.87) sit in the middle half of the list.
0.50 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.27 in.
- Tangential
- 8.4%
- Radial
- 4.5%
- Volume
- 12.6%
- T/R ratio
- 1.87 (87th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Para-angelim
6% harder · same density · shrinks 1.3 points less across the face
- Black locust
4% harder · 5% heavier · shrinks 1.2 points less across the face
- Angelique
21% softer · 5% lighter · shrinks 0.4 points more across the face
Woods of similar hardness
The eight nearest on the Janka scale, lbf.
Laboratory values
Its most unusual laboratory figure is shear strength: 7th highest of the 154 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Shear parallel to grain | 1,900psi | 2,480psi | +31% | 17.1MPa |
| Compression parallel to grain | 7,480psi | 10,400psi | +39% | 71.7MPa |
| Modulus of rupture | 13,600psi | 17,400psi | +28% | 120MPa |
| Side hardness | 1,520lbf | 1,630lbf | +7% | 7,251N |
| Modulus of elasticity | 1.73M psi | 1.94M psi | +12% | 13.4GPa |
| Work to maximum load | 12.2in-lbf/in³ | 14.4in-lbf/in³ | +18% | 99.3kJ/m³ |
Wood Handbook Table 5-5b, Table 4-4. Data & method · Guides