USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technical Fact Sheet
and T. africana
Other Common Names: (T. heckelii) Baku (Ghana), Makore (Ivory Coast); (T. africana) Douka, Ukola (Gabon).
Distribution: Both species together are found from Sierra Leone to Cameroon, Gabon, and south to Cabinda; widely distributed in the high rain forests.
The Tree: Reaches a height of 180 to 200 ft; boles straight, cylindrical, and clear to 100 ft, free of buttresses; trunk diameters generally about 4 ft but may be up to 10 ft.
General Characteristics: Heartwood pink to pink- or red brown; sapwood 2 to 3 in. wide, whitish or light pink, clearly demarcated. Texture fine to medium; grain generally straight; lustrous; sometimes with an attractive moire figure. Liable to stain in contact with iron when damp.
Weight: Basic specific gravity (ovendry weight/green volume) about 0.55; air-dry density 42 pcf.
Mechanical Properties: (2-cm standard)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (16) 10,900 1,190 5,300
12% 14,700 1,470 7,730
12% (47) 17,400 1,630 9,700
12% (47) 16,000 1,460 8,100
Janka side hardness 930 lb for green material and 1,110 lb for dry. Amsler toughness 126 in.-lb at 12% moisture content (2-cm specimen).
Drying and Shrinkage: Dries at a slow to moderate rate with little degrade. Kiln schedule T10-D4S is suggested for 4/4 stock and T8-D3S for 8/4 (T. heckelii). Shrinkage green to ovendry; radial 4.7 to 6.2%; tangential 6.8 to 8.0%; volumetric 10.6 to 11.0%. Movement in service is rated as small.
Working Properties: A high silica content causes blunting of cutting edges, particularly in dry wood; works reasonably well with hand and machine tools, good veneering properties, finishes well, good gluing properties. Fine dust may irritate nose and throat or cause dermatitis.
Durability: Heartwood is highly durable and resistant to termite attack; sapwood liable to powder-post beetle attack.
Preservation: Heartwood is extremely resistant to preservative treatments; sapwood moderately resistant.
Uses: Furniture, cabinetwork, joinery, decorative veneers, paneling, boatbuilding, flooring, turnery, marine plywood.
Additional Reading: (3), (9), (16), (47)