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

Wood Technical Fact Sheet

 Swintonia spp.

Merpauh

Family: Anacardiaceae

Other Common Names: Selan (Sarawak), Boilam (India), Taung-thayet (Burma), Khan thong (Thailand).

Distribution: Burma and the Malayan Peninsula eastward into Borneo, Cambodia, and the Philippines.

The Tree: A large tree with clear boles to 80 ft; trunk diameters 3 to 4 ft; base of stems often fluted with high buttresses.

The Wood:

General Characteristics: Heartwood grayish white, yellow brown, light red brown, narrow lighter colored striping often on radial faces and dark zigzag figure on tangential faces; sapwood not clearly differentiated. Texture moderately coarse; grain straight to interlocked; lustrous when freshly cut; without characteristic odor or taste. Some species are siliceous.

Weight: Basic specific gravity (ovendry weight/green volume) 0.61; air-dry density 46 pcf.

Mechanical Properties: (2-in. standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

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

Green (36) 11,520 2,115 5,710

18% 14,750 2,310 7,110

Green (38) 8,625 1,640 4,095

14% 11,435 1,850 5,590

Janka side hardness 740 to 1,070 lb for green material and 850 to 1,300 lb for dry.

Drying and Shrinkage: Air seasons fairly rapidly, only slight bowing and twisting, some end-checking; prone to staining. No information available on kiln schedules. Shrinkage green to ovendry: radial 3.2%; tangential 6.0%; volumetric 10.8%.

Working Properties: Tension wood is rather common causing difficulty in sawing and woolly finish, otherwise works rather well.

Durability: Heartwood is not durable and sapwood is particularly prone to stain.

Preservation: Heartwood reported to be treatable with absorption of 7 to 17 pcf of preservative oils using an open-tank system.

Uses: Boatbuilding, light construction, packing cases, rotary veneer, matches.

Additional Reading: (9), (11), (36), (38), (47)