USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
(608) 231-9200

 

Wood Technical Fact Sheet

 

 Irvingia gabonensis

Oba

Family: Irvingiaceae

Other Common Names: Bobo (Sierra Leone), Boboru, Wanini (Ivory Coast), Andok (Cameroon), Meba, Mueba (Zaire), Oro, Oba (Nigeria).

Distribution: Western tropical Africa from Senegal to Angola; often found near riverbanks and reaches its optimum in the dense evergreen rain forest.

The Tree: A deciduous tree reaching a height of 100 ft; bole usually straight and cylindrical slightly buttressed; trunk diameter 3 to 5 ft.

The Wood:

General Characteristics: Heartwood pale green brown or orange yellow, fading on exposure to a gray brown, sometimes with dark gray streaks; sapwood lighter, not always differentiated. Texture fine to medium; grain straight to interlocked; without luster.

Weight: Basic specific gravity (ovendry weight/green volume) 0.67 to 0.75; air- dry density 52 to 58 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

(%) (Psi) (1,000 psi) (Psi)

12% (47) 23,600 2,710 11,400

Amsler toughness 288 in.-lb at 12% moisture content (2-cm specimen).

Drying and Shrinkage: Logs should be converted soon after felling, preferably by quartersawing, to avoid end and surface checking. No information on kiln schedules. Shrinkage green to ovendry: radial 6.8%; tangential 11.4%; volumetric 18.0%.

Working Properties: Moderately difficult to saw and plane, tool edges must be kept sharp, dresses to a smooth finish, glues well.

Durability: Heartwood is durable with little or no termite attack. Good weathering properties.

Preservation: Heartwood is untreatable; sapwood is resistant to preservative treatments.

Uses: Heavy construction, railroad crossties. The tree yields the dika nut, has an edible fruit somewhat like a mango, and kernels that are a source of edible fats.

Additional Reading: (3), (6), (47)