USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technology Transfer Fact Sheet
Other Common Names: Kyenkyen, Chenchen (Ghana), Mkuzu, Mlulu (Tanzania), Oro, Ogiovu (Nigeria), Kirundo, Mumaka (Uganda), Ako (Dahomey, Senegal).
Distribution: Distributed throughout the high forest zone of West, Central, and East Africa on widely varying sites.
The Tree: Reaches a height of 120 to 150 ft with a straight, cylindrical bole clear to 70 ft; trunk diameters 2 to 5 ft; sometimes buttressed.
General Characteristics: Wood is whitish or light yellow brown with no distinction between sapwood and heartwood. Texture medium to coarse; grain interlocked; lustrous; without characteristic odor or taste when dry, but has an unpleasant odor when green.
Weight: Basic specific gravity (ovendry weight/green volume) 0.38; air-dry density 27 pcf.
Mechanical Properties: (First set of data based on the 2-in. standard, second and third sets on the 2-cm standard.)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
Green (4) 4,770 810 2,930
12% 7,270 960 5,090
12% (44) 6,040 820 4,500
12% (40) 8,550 1,040 5,400
Janka side hardness 380 lb for green and 500 lb for dry material. Amsler toughness 50 in.-lb for dry material (2-cm specimen).
Drying and Shrinkage: Seasons rather rapidly but there is a pronounced tendency to warp, particularly twisting. Kiln schedule T2-D4 is suggested for 4/4 stock and T2-D3 for 6/4. Shrinkage green to ovendry: radial 4.2%; tangential 6.8%; volumetric 12.4%. Movement in service is rated as small.
Working Properties: Works easily with hand and machine tools but sharp cutters are needed; dresses smoothly, some tearing of interlocked grain; glues and nails satisfactorily.
Durability: Wood is perishable and liable to ambrosia beetle and powder-post beetle attack. Very susceptible to sap stain, requires rapid extraction and chemical treatments.
Preservation: Easy to treat using either open tank or pressure systems.
Uses: Veneer and plywood, furniture components, joinery, boxes and crates, light construction.
Additional Reading: (4), (9), (40), (44)
4. Bryce, J. M. 1966. The strength properties of Tanzania timbers. Util. Sec. For. Div. Tec. Note No. 35.
9. Farmer, R. H. 1972. Handbook of hardwoods. H. M. Stationery Office. London.
40.Lavers, G. M. 1967. The strength properties of timbers. For. Prod. Res. Bul. No. 50. H. M. Stationery Office. London.
44.Sallenave, P. 1955. Proprietes et mecaniques des bois tropicaux de l'union Francaise. Pub. Centre Tech. For. Trop. No. 8.
From: Chudnoff, Martin. 1984. Tropical Timbers of the World. USDA Forest Service. Ag. Handbook No. 607.