Tropical wood · Africa
Opepe wood
Opepe (Nauclea diderrichii, family Rubiaceae) is a tropical timber from Africa. Dry, its Janka hardness is 1,630 lbf (7,251 N), and air-dry it weighs about 47 lb/ft³ (753 kg/m³). The figures are from the USDA Forest Products Laboratory's Tropical Timbers of the World, pp. 467–468.
Other names, by country: Kusia (Ghana), Badi (Ivory Coast), Bilinga (Gabon), Akondoc (Cameroon), N'Gulu-maza (Zaire), Kilingi (Uganda).
Key numbers
- Janka hardness, dry
- 1,630 lbf (7,251 N)
- Green: 1,520 lbf (6,761 N)
- As printed: “Janka side hardness 1,520 lb for green and 1,630 lb for dry material.”
- Air-dry density
- 47 lb/ft³ (753 kg/m³)
- Basic specific gravity
- 0.63 oven-dry weight, green volume
- As printed: “Basic specific gravity (ovendry weight/green volume) 0.63; air-dry density 47 pcf.”
- Shrinkage, green to oven-dry
- 8.4% tangential
- Radial 4.5%, volumetric 12.6%
One source: USDA Forest Products Laboratory, Tropical Timbers of the World (Chudnoff, 1979 edition), the only published source read for this wood
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE); crushing strength is compression parallel to the grain. The sheet collects these from published tests: it prints 3 data sets, from different tests and sources, so they can differ widely; all are shown, in the sheet's order, each at the moisture content printed beside it, never restated as 12%.
| Moisture | Bending strength (MOR) | Stiffness (MOE) | Crushing strength |
|---|---|---|---|
| Green | 13,700 psi (94 MPa) | 1.72 million psi (11.9 GPa) | 7,490 psi (52 MPa) |
| 12% MC | 17,400 psi (120 MPa) | 1.94 million psi (13.4 GPa) | 10,400 psi (72 MPa) |
| 12% MC | 15,000 psi (103 MPa) | 2 million psi (13.8 GPa) | 8,600 psi (59 MPa) |
A dash means the sheet prints no value; none is filled in.
What the data sheet says
- Color, grain and texture
- Heartwood orange or golden-yellow, darkening on exposure; sapwood whitish or pale yellow, clearly defined. Texture rather coarse; grain usually interlocked or irregular; lustrous; without characteristic odor or taste. An alkaloid in the wood may be toxic to woodworkers.
- Working properties
- Timber works moderately well with hand and machine tools, requires a slow feed in sawing, a 10 degree cutting angle is suggested for planing to prevent tearing; good gluing; takes a satisfactory finish. Poor steam-bending characteristics.
- Durability
- Heartwood is rated as very durable but is moderately resistant to termites. Sapwood liable to powder-post beetle attack. Heartwood resistant to marine borers.
- Uses
- Dock and marine work, boatbuilding (except bent work), railway crossties, general construction, flooring, furniture and cabinet parts.
- Where it grows
- Widely distributed from Sierra Leone to the Congo region and eastward to Uganda; often found in pure stands.
Quoted from Tropical Timbers of the World, pp. 467–468, a USDA Forest Products Laboratory work in the public domain.
Work it out for your project
- Rank woods for furniture with the species picker
Weigh opepe against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.