Properties and Uses

Jelutong

The Standard Malaysian Name for the timber of Dyera spp. (Apocynaceae). The timber is a light hardwood with a density of 420–500 kg m^–3air dry. The sapwood is not distinguished from the heartwood, which is creamy white to pale straw-coloured. Living parenchyma cells have been found in the wood next to the pith and it appears that this tree does not produce any true heartwood. Texture is moderately fine and even, with almost straight grain. The timber is weak (Strength group D). It is easy to saw and plane and produces a smooth surface despite its softness. Nailing property is excellent. The timber seasons fairly rapidly without serious degrade, except for staining and powder-post beetle attacks but the common practice of dipping the timber in preservatives immediately after sawing has largely overcome this problem. 13 mm boards take 1.5 months to air dry, while 38 mm boards take 3 months. Shrinkage is fairly low, with radial shrinkage averaging 0.8% and tangential shrinkage averaging 2%. The movement of seasoned timber is classified under Type II. The timber is highly perishable, susceptible to fungal attacks as well as lyctus beetle and termite attacks. The timber is, however, easily treated with preservatives.

USES: The timber is suitable for pattern making, carving, picture frames, drawing boards, black boards, toys, packing cases, wooden shoe heels. It is also the favourite wood for pencil manufacture.

Vernacular names applied include jelutong (P.M., Sab. and Sar.) with various epithets. Major species include D. costulata and D. polyphylla.