Chengal

• Straight-boled (trunk), large hardwood.
• Grows to 25m high on good sites.

• Occurs in peninsular Malaysia in a wide range of conditions from low-lying swamp flats to hills at 10,000m.
• Limited occurrence in Thailand.

Colour

• Sapwood is pale yellow and well defined.
• Heartwood is yellow to dark brown, often with a green tinge.

Grain

• Grain is usually slightly interlocked producing a vague ribbon figure (pattern) on the radial face.
• Even, medium texture.

• Engineering: structural members requiring high strength and durability, railway sleepers, wharf and bridge constructions, poles, piles, mining timbers.
• Construction: heavy duty flooring, decking.
• Others: boat building, truck bodies, casks, vats, churns.

• Density: 930kg/m³ at 12% moisture content; about 1.0m³ of seasoned sawn timber per tonne.
• Strength groups: S1 unseasoned, SD2 seasoned.
• Stress grades: F14, F17, F22, F27 (unseasoned); F17, F22, F27, F34 (seasoned) when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes.
• Joint groups: JD2 seasoned.
• Shrinkage to 12% MC: 6.3% (tangential), 1.0% (radial).
• Unit shrinkage: not available.
• Durability above-ground: Class 1 (life expectancy more than 40 years).
• Durability in-ground: Class 1 (life expectancy more than 25 years).
• Lyctine susceptibility: sapwood is not susceptible to lyctine borer attack.
• Termite resistance: resistant.
• Preservation: sapwood moderately resists treatment with preservatives.
• Seasoning: slow seasoning timber with very low shrinkage and dries with minimal degrade.
• Hardness: hard (rated 1 on a 6-class scale) to indent and work with hand tools.
• Machining: works well for a high-density timber except for the presence of resin; a cutting angle of 20° recommended on interlocked, quarter-sawn material to prevent 'picking-up'.
• Fixing: pre-drill before nailing.
• Gluing: due to high density, machine and prepare surface immediately before gluing.
• Finishing: be careful due to the resin; obtains a good finish.

General characteristics

• Sapwood: well defined from heartwood.
• Heartwood: dark tan brown, lustrous planed surface, sometimes with subdued strip figure (pattern).
• Texture: moderately fine and even, interlocked grain, hard to cut across the grain.

Wood structure

• Vessels: medium size, mainly solitary, others in radial pairs or short multiples, evenly distributed; filled with tyloses.
• Parenchyma (soft tissue): numerous, short, fine apotracheal strands and closely spaced tangential lines, often not clearly visible with hand lens.
• Rays: moderately fine, not easily seen on a radial surface.
• Ripple marks: characteristic and very distinct.
• Intercellular canals: vertical canals, smaller than vessels, filled with white resin, concentric and often discontinuous.

Other features

• Burning splinter test: match-size splinter burns to ash.

• Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
• Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
• Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.