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

Wood Technical Fact Sheet

 Triplochiton scleroxylon

Obeche

Family: Sterculiaceae

Other Common Names: Arere, Obeche (Nigeria), Samba (Ivory Coast), Ayous (Cameroon), Wawa (Ghana), Abachi (Germany, Holland).

Distribution: Widely distributed in tropical West Africa from Guinea to Cameroon; predominantly along waterways and on abandoned farms in the transition zone between the humid evergreen and semideciduous forests.

The Tree: A large tree 150 to 180 ft in height, boles straight, cylindrical, and clear to 80 ft; buttresses may reach to 20 ft; trunk diameters to 5 ft.

The Wood:

General Characteristics: Timber whitish to pale straw with no difference between heartwood and sapwood. Texture medium to coarse; grain typically interlocked, giving a striped figure; lustrous; has an unpleasant smell when green but usually does not persist after drying.

Weight: Basic specific gravity (ovendry weight/green volume) 0.32; air-dry density 24 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (9) 5,400 660 2,680

12% 7,900 800 4,090

12% (47) 8,800 940 4,300

Janka side hardness 420 lb for green material and 430 lb for dry. Amsler toughness 105 in.-lb at 12% moisture content (2-cm specimen).

Drying and Shrinkage: Dries very rapidly and with little or no degrade, slight warp though, may occur. Kiln schedule T14-C6S is suggested for 4/4 stock and T12-C5S for 8/4. Shrinkage green to ovendry: radial 3.0%; tangential 5.4%; volumetric 9.2%. Movement in service is rated as small.

Working Properties: Works very easily with hand and machine tools but sharp edges are needed for a smooth finish, veneers easily, good gluing and nailing properties.

Durability: Heartwood is not durable and liable to termite and other insect attack; sapwood prone to powder-post beetle attack. Logs must be extracted from the forest and converted rapidly to avoid deterioration by fungi and insects.

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

Uses: Furniture components, plywood, joinery, millwork, boxes and crates, blockboard, particle and fiberboard, patternmaking, artificial limbs.

Additional Reading: (3), (9), (20), (47)