Botanical Name: Koompassia spp.

Kempas has a medium to coarse open texture. The grain is interlocked and sometimes wavy. The wood can also have streaks of brittle tissue that can be a source of mechanical weakness.

Kempas is considered to be a difficult timber to work on account of both its density and its interlocked grain. Also, sections of the wood may contain stone-like streaks of brittle areas, which can have a blunting effect on cutting edges, and make machining difficult. Kempas is slightly acidic and can be corrosive to metals. The wood accepts stains and finishes well.

Kempas is used for external cladding, flooring, heavy construction, railroad cross ties, plywood, and pallets (throughout its natural range).

Density 880 kg/m3
Strength Groups S2 unseasoned; SD2 seasoned
Stress Grades F8, F11, F14, F17, F22 (unseasoned), F17, F22, F27, F34 (seasoned)
Joint Groups J3 unseasoned; JD2 seasoned
Shrinkage to 12% MC 3.0% (tangential); 2.0% (radial)
Unit Shrinkage Not available
Durability Above-ground Class 3 – life expectancy 7 to 15 years
Durability In-ground Class 3 – life expectancy 5 to 15 years
Lyctine Suceptibility Untreated sapwood susceptible to lyctid borer attack
Termite Resistance Not Resistant
Preservation Sapwood accepts preservative impregnation
Seasoning Included phloem (bark) causes the timber to split during drying, but clean material seasons well if care taken
Hardness Hard (rated 2 on a 6 class scale) in relation to indentation and ease of working with hand tools
Machining Interlocking grain can cause difficulty as does the fibrous nature of kempas. Difficult to work with hand tools.
Fixing Pre-boring advised when nailing close to edges.. The timber is slightly acidic and may corrode iron fastenings.
Gluing Can be satisfactorily bonded using standard procedures.
Finishing Kempas can be sanded to a good finish but requires filling prior to finish. Stains and accepts paint well.