Description
The Standard Malaysian Name for the timber of Koompassia malaccensis (Leguminosae). Vernacular names applied include impas (Sabah) and menggris (Sarawak). Kempas is a monospecific timber. This timber is very common of the lowland forests and swampy regions of the island states of Malaysia and Indonesia normally growing to height of about 55 metres. Kempas is a Medium Hardwood with a density of 770-1,120 kg/m3 air dry. It was reported that the material from Sabah and Sarawak is much denser than the material from Peninsular Malaysia.

The timber dries quickly with low shrinkage rates between 2 to 3%, but has a tendency to split so care should be taken in the process, although it is very stable in service. No silica is present, however being so hard the timber is difficult to work particularly with hand tools.


Appearance

The heartwood is dark pink to reddish brown darkening with age and often having yellowish streaks which slightly confuse it with the sapwood which is pale yellow to light pinkish brown. Apart from these streaks it is usually easy to define and is susceptible to lyctid borer attack.

This timber is classified as moderately durable. In a test conducted at the Forest Research Institute Malaysia (FRIM), the average service life for 161 untreated specimens was 2.5years. The sapwood is very susceptible to both powder-post beetles and fungi attacks, while the heartwood is readily destroyed by termites. Kempas treated with the appropriate wood preservatives is very durable even under exposed condition. In an experiment, 40 test sticks (64 mm x 64 mm x 760 mm) with an average absorption of 224 kg/m3 (14 lb/ft3) of creosote were buried for the durability test. 25% of the specimens were destroyed after 35 years.

Texture is rather coarse but even except in areas where included phloem occurs. Grain is interlocked, often very interlocked.


Strength Properties
The timber falls into Strength Group A.