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

Wood Technical Fact Sheet

 Dyera costulata

Jelutong

Family: Apocynaceae

Other Common Names: Jelutong bukit (Sarawak).

Distribution: Malaysia and Brunei.

The Tree: May reach a height of 200 ft, with straight and cylindrical boles free from buttresses to lengths of 90 ft; trunk diameters up to 8 ft.

The Wood:

General Characteristics: Heartwood creamy white to pale straw not differentiated from sapwood. Grain mostly straight; texture moderately fine and even; slightly lustrous without taste but has a slight sour odor that is distinctive. Marked with latex traces or canals often in clusters 2 to 3 ft apart along the stem.

Weight: Basic specific gravity (ovendry weight/green volume) 0.36; air-dry density 28 pcf.

Mechanical Properties: (2-in. standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (37) 5,570 1,155 3,050

16% 7,315 1,180 3,920

Janka side hardness 330 lb for green material and 390 lb for dry.

Drying and Shrinkage: Dries easily with little or no degrade. Kiln schedule T10-4DS is suggested for 4/4 stock and T8-D3S for 8/4. Shrinkage green to ovendry: radial 2.3%; tangential 5.5%; volumetric 6.2%. Movement in service is rated small.

Working Properties: Works easily with hand and machine tools but may gum the cutter excellent for carving; glues satisfactorily.

Durability: Nondurable, prone to sap stain, and is readily attacked by termites and powder-post beetles.

Preservation: Reported to absorb preservatives readily and is easily treated using the open tank system.

Uses: Patternmaking, drawing boards, carvings, wooden shoes, picture frames, pencil slats. The tree yields a latex used in the manufacture of chewing gum.

Additional Reading: (9), (17), (37)