USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
Wood Technical Fact Sheet
Other Common Names: Ozigo, Assia, Igaganga, Ossabel (Gabon), Safoukala (Congo-Brazzaville), Mouguengueri (Zaire).
Distribution: West Africa, prevalent in rain forests.
The Tree: Height variable with species, may reach 120 ft; bole usually straight and cylindrical, most species not buttressed; trunk diameters 2 to 5 ft.
General Characteristics: Heartwood pink, gray buff or yellowish; not clearly demarcated from the sapwood. Texture moderately fine to coarse; grain straight, wavy, or interlocked; sometimes lustrous; gum ducts and silica present.
Weight: Basic specific gravity (ovendry weight/green volume) variable with species mostly 0.54 to 0.67; air-dry density 41 to 51 pcf.
Mechanical Properties: (2-cm standard)
Moisture content Bending strength Modulus of elasticity Maximum crushing strength
(%) (Psi) (1,000 psi) (Psi)
12% (44) 18,600 1,840 10,100
12% (44) 16,500 1,840 8,100
12% (44) 18,600 2,710 8,900
Amsler toughness 128 to 410 in.-lb for dry material (2-cm specimen).
Drying and Shrinkage: Generally reported to require careful seasoning to avoid severe degrade due to checking and warping. No data available on kiln schedules. Shrinkage green to ovendry: radial 4.4 to 7.5%; tangential 5.8 to 8.2%; volumetric 13.0 to 15.6%.
Working Properties: Rather difficult to saw because of silica content but generally reported to work fairly well with hand and machine tools; good slicing and peeling characteristics; glues readily and takes a fine finish.
Durability: Heartwood has moderate to low resistance to attack by decay fungi, also liable to termite attack.
Preservation: Generally heartwood resistant to preservative treatments, sapwood moderately resistant.
Uses: Flooring, furniture components, veneer and plywood, joinery.
Additional Reading: (3), (38), (44)