Properties and Uses

Keranji

The Standard Malaysian Name for the timber of Dialium spp. (Leguminosae). The timber is a heavy hardwood with a density of 755–1250 kg m^–3air dry. The sapwood is white to yellowish white, becomes light brown on exposure and is very distinct from the heartwood, which is golden brown or red-brown and darkens on exposure. Texture is fine to moderately coarse and even, with deeply interlocked and sometimes wavy grain. The timber is extremely strong (Strength group A). It is easy to very difficult to resaw and easy to difficult to cross-cut, depending on the species. Planing is easy to slightly difficult and the planed surface is smooth, moderately smooth or rough in some radial boards due to picking-up of the grain. Nailing property is rated good. The timber seasons fairly slowly with slight degrade, like cupping, bowing, twisting, splitting, surface-checking and insect and fungal attacks on the sapwood. The timber is also moderately prone to end-checking. 13 mm boards take approximately 2 months to air dry, while 38 mm boards take 6 months. Shrinkage is variable, depending on species. Dialium platysepalum shows a high shrinkage in that radial shrinkage averages 2.3% and tangential shrinkage averages 3.7%. Dialium platysepalum shows rather low shrinkage in that radial shrinkage averages only 1% and tangential shrinkage averages 1.7%. The movement of seasoned timber is classified under Type II. For kiln-drying, Schedule E is recommended. The timber is prone to surface-checking and end-splitting. 25 mm boards take approximately 10 days to kiln-dry from 50 to 10% moisture content. The timber is moderately durable and the heartwood is resistant to preservative treatment.

USES: The timber is suitable for heavy construction, interior finishing, panelling, parquet flooring, strip flooring, handles for striking tools, police batons, heavy duty flooring and power-line poles.

Vernacular names applied include keranji (P.M., Sab. and Sar.) with various epithets. Major species include D. indum, D. platysepalum, D. procerum and D. kunstleri.