USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
(608) 231-9200

Wood Technical Fact Sheet

 Koompassia malaccensis

Kempas

Family: Leguminosae

Other Common Names: Impas (Sabah), Mengris (Sarawak).

Distribution: Malaysia and Indonesia; throughout lowland forests in rather swampy areas and also on hillsides.

The Tree: May reach a height of 180 ft with clear, usually straight boles to 80 to 90 ft, trunk diameters may reach 6 ft and more over heavy buttresses.

The Wood:

General Characteristics: Heartwood brick red when freshly cut, darkening on exposure to an orange red or red brown with numerous yellow-brown streaks due to soft tissue associated with the pores; sapwood white or pale yellow about 2 in. wide in large trees and clearly defined. Grain typical- interlocked, sometimes wary; texture rather coarse; luster variable; odor and taste not distinctive. The timber is

slightly acidic and may be corrosive to metals. Streaks of brittle stone-like tissue are fairly common and are a source of mechanical weakness.

Weight: Basic specific gravity (ovendry weight/green volume) 0.72; air-dry density 55 pcf.

Mechanical Properties: (2-in. standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (37) 14,530 2,410 7,930

15% 17,680 2,690 9,520

Janka side hardness 1,480 lb for green material and 1,710 lb for dry.

Drying and Shrinkage: The timber usually dries well though with some tendency to warping and checking. If included phloem is present, splits are liable to develop. Kiln schedule T6-02 is suggested for 4/4 stock and T3-D1 for 8/4. Shrinkage green to ovendry: radial 6.0%; tangential 7.4%; volumetric 14.5%. Reported to hold its place well once seasoned.

Working Properties: The timber is difficult to work with hand and machine tools; dresses to a reasonably smooth surface.

Durability: Reported to be resistant to attack by decay fungi but vulnerable to termite activity, both subterranean and dry-wood. Sapwood liable to powder-post beetle attack.

Preservation: Reported to treat readily with absorptions of preservative oils as high as 20 pcf.

Uses: Heavy construction work, railroad crossties, plywood core stock, parquet flooring, pallets (should be treated where termite attack may be a particular hazard).

Additional Reading: (9), (11), (18), (37)