Keruing is produced by 70 or so species of the genus Dipterocarpus.  They are large hardwoods, some species attaining a height of 70 metres.
 
 
Keruing occurs throughout Indonesia, Malaysia, Philippines, Sabah, Sarawak, Brunei, Pakistan, India, Burma, Borneo, Thailand, Sri Lanka and Kampuchea.

Wood appearance
Colour. Heartwood varies between species but is most commonly red-brown.  Variations include deep-pink, orange-pink, purple-red.  Sapwood is usually lighter in shade and may have yellow or greyish tinges.  Wood darkens with age.

Grain. Grain is generally straight but may be slightly interlocked resulting in some stripe figure on the radial surface.  Texture varies between species and area of origin from fine to coarse but even.

Wood properties
Density. 790 kg/m3 at 12 % moisture content; approximately 1.3 m3 of seasoned sawn timber per tonne.

Strength Group. S3 unseasoned, SD3 seasoned.

Stress Grades. F8, F11, F14, F17 (unseasoned), F14, F17, F22, F27 (seasoned), when visually stress graded in accordance with AS2082-2000, ‘Visually stress-graded hardwood for structural purposes.’

Shrinkage to 12% MC. Shrinkage varies between species but averages approximately 7.0 % (tangential); 3.5 % (radial).

Unit Shrinkage. Not available.

Durability. Class 4 – Suitable for use only in continuously dry situations under cover, well ventilated, clear of the ground and fully protected from the weather and other dampness.

Lyctid Susceptibility. Untreated sapwood susceptible to lyctid borer attack.

Preservation. Keruing is moderately resistant to impregnation with preservatives, resulting in a possibility of uneven distribution of preservative.

Seasoning. Difficult to season without degrade causing checks, splits and warping.  Pre-steaming before drying can reduce degrade. 

Hardness. Moderately hard (rated 3 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining. The presence of silica and resin can make machining difficult.  Cutting edges must be kept sharp, and tungsten-tipped tools give best results. 

Fixing. Nails satisfactorily; stock may stain with iron fastenings.

Gluing. Gluing qualities variable.

Finishing. Stock with high resin content has a poor base for all finish coatings.  Less resinous stock finishes satisfactorily.

Uses
Construction. Laboratory flooring (has good acid resistance) internal flooring, protected framing and boards.
 
Decorative.
Internal joinery and mouldings, lining, panelling. 

Others.  Framework of carriages and wagons.

Identification features
General characteristics

Sapwood. Grey-brown, distinct from heartwood.

Heartwood. Red brown to dark brown.

Texture. Moderately coarse, uniform, straight grain.
 
 
Wood structure

Vessels. Predominantly solitary, large, visible to the naked eye, uniform diffuse distribution.  Heavily tylosed in some species, but not in others.

Parenchyma. Apotracheal and paratracheal; apotracheal as scattered or confluent patches containing vertical resin canals; paratracheal very sparse as borders to vessels, often distinct.

Rays. Of two distinct sizes; medium and small.  Medium size visible to the naked eye, quite prominent on radial surfaces.

Other features

Burning Splinter Test. The wood burns to an ash.