Tropical wood · Africa
Nkobakoba wood
Nkobakoba (Baikiaea insignis subsp. minor, family Leguminosae) is a tropical timber from Africa. Dry, its Janka hardness is 1,770 lbf (7,873 N), and air-dry it weighs about 50 lb/ft³ (801 kg/m³). The figures are from the USDA Forest Products Laboratory's Tropical Timbers of the World, pp. 337–338.
Other names, by country: Nkoba (Uganda).
Key numbers
- Janka hardness, dry
- 1,770 lbf (7,873 N)
- As printed: “Janka side hardness 1,770 lb for dry material.”
- Air-dry density
- 50 lb/ft³ (801 kg/m³)
- Basic specific gravity
- 0.65 oven-dry weight, green volume
- As printed: “Basic specific gravity (ovendry weight/green volume) 0.65; air-dry density 50 pcf.”
- Shrinkage, green to air-dry
- 4.5% tangential
- Radial 2.3%
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 one data set, each at the moisture content printed beside it, never restated as 12%.
| Moisture | Bending strength (MOR) | Stiffness (MOE) | Crushing strength |
|---|---|---|---|
| 12% MC | 17,035 psi (117 MPa) | 2.62 million psi (18 GPa) | 9,460 psi (65 MPa) |
A dash means the sheet prints no value; none is filled in.
What the data sheet says
- Color, grain and texture
- The wood is straw or more yellowish with a pinkish tinge turning a grayish-brown on drying, often marked with darker streaks, little or no distinction between sapwood and heartwood. Texture medium; grain straight; when worked, the wood has a green fig odor, tasteless.
- Working properties
- Green timber difficult to saw because gummy sawdust clogs the teeth and blade; but works easily with hand and machine tools, some tearing of grain in planing.
- Durability
- The wood is rated as nondurable and is very liable to beetle and termite attack.
- Uses
- Flooring, heavy construction (treated), furniture components.
- Where it grows
- Abundant in the South Buddu forests of Uganda and the Bukoba district of Tanzania; found in riverain, lakeshore, and swampy localities.
Quoted from Tropical Timbers of the World, pp. 337–338, 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 nkobakoba against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.