Octomeles sumatrana

Binuang

Family: Tetramelaceae

Other Common Names: Erima, limo (New Guinea), Benuang (Indonesia).

Distribution: Extends from Sumatra to Papua and the Solomons and northwards to the Philippines; a low altitude riverine species, often in almost pure stands.

The Tree: Reaches a height over 180 ft with a clear bole 70 ft or more, good form; trunk diameters 5 ft or more. Some trees have heavy buttresses that may reach 12 to 15 ft. above the base.

The Wood:

General Characteristics: Heartwood pale yellow, buff to pale brown or pinkish brown sapwood whitish, wide, not always clearly defined. Grain interlocked; texture coarse; luster low; without distinctive odor or taste. Brittle heart is frequently present.

Weight: Basic specific gravity (ovendry weight/green volume) 0.32; air-dry density 23 pcf.

Mechanical Properties: (2-in. standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (7) 5,250 950 3,300

12% 7,700 1,190 5,270

Green (35) 5,400 770 3,160

12% 7,550 915 4,800

Janka side hardness 355 to 370 lb for dry material. Forest Products Laboratory toughness 54 in.-lb for green material and 44 in.-lb for dry (5/8-in. specimen).

Drying and Shrinkage: Dries slowly with severe degrade in the heartwood-sapwood zone. Some sources report this wood to dry without difficulty. Kiln schedule T3-C2 is suggested for 4/4 stock and T3-C1 for 8/4. Shrinkage green to 12% moisture content: radial 3.0%; tangential 7.0%. Movement in service is rated as small.

Working Properties: The timber works easily with hand and machine tools but sharp knives are needed to avoid a woolly finish; a poor finish is usually obtained in crosscutting and drilling; nails satisfactorily.

Durability: Heartwood is perishable and highly susceptible to termite attack. Sapwood liable to powder-post beetle attack.

Preservation: Heartwood is moderately resistant to preservative treatments, sapwood however, is responsive to both open-tank and pressure-vacuum systems.

Uses: Backs and cores of plywood, form work, light construction, furniture components, burial caskets, cabinetwork, shingles and shakes.

Additional Reading: (7), (9), (17), (35)

M 150 282-3Logs are delivered to a sawmill in southern Nigeria. African mahogany

(mostly Khaya ivorensis) is in high demand on overseas markets. Export of logs fro

this region, as well as from most other tropical areas, is being restricted.

M 150 282-2Band mills in Ghana are designed to handle logs 5 feet and more in

diameter. Obeche or Wawa (Triplochiton scleroxylon) logs yield lumber favored for

joinery and millwork.

M 150 273-14In many areas of the tropics, fast-growing species are being introduced

future supplies of fuel wood and industrial wood. Batai (Albizia falcataria) is

a favored plantation species in the Philipines.