Okoume (Aucoumea klaineana) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Okoume |
|---|---|
| Janka side hardness, 12% moisture | 380 lbf (1,690 N) |
| Janka side hardness, green | not reported |
| Hardness rank | harder than 7 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 24.8 lb/ft³ (396 kg/m³)* |
| Weight per board foot (12%) | 2.06 lb* |
| Specific gravity (ovendry weight, green volume) | 0.33 |
| Specific gravity at 12% moisture | 0.35* |
| Bending strength (modulus of rupture), 12% | 7,400 psi |
| Stiffness (modulus of elasticity), 12% | 1.14 million psi |
| Crushing strength (compression parallel to grain), 12% | 3,970 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 4.1% / 6.1% / 11.3% |
| Tangential / radial shrinkage ratio | 1.49 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00194 / 0.00212 |
| Heartwood decay resistance | slightly or nonresistant |
What it is
Okoume (Aucoumea klaineana) has a restricted natural range in west-central Africa, mainly Gabon and its neighbours, but it is planted extensively within that range. The heartwood is salmon pink and the narrow sapwood whitish or pale grey. The wood has a high lustre and a uniform texture slightly coarser than birch.
Most okoume reaches buyers as plywood rather than lumber. Its light weight, even texture and ease of peeling make it one of the main face and core species for lightweight plywood, including marine plywood made to the British BS 1088 standard that boatbuilders use.
Working properties
Okoume is light and soft: about 24.8 lb per cubic foot at 12% moisture content (our estimate from specific gravity) and 380 lbf of Janka hardness, about the same as eastern white pine. Sawn lumber is somewhat difficult to machine because of its silica content, which dulls cutters, but the wood glues, nails and peels into veneer easily.
The Handbook points out its flexibility in finishing: the colour is of medium intensity, so it can be toned lighter or darker. The heartwood is nondurable and sits in the slightly or nonresistant decay class, which is why okoume boat plywood is always fully encapsulated in epoxy or paint.
Weight and density
At 12% moisture content okoume weighs about 24.8 lb per cubic foot (estimated from its specific gravity and shrinkage), so one board foot (144 cubic inches) weighs about 2.06 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 5.7 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 7.2 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
Wood movement
The Wood Handbook gives dimensional change coefficients for each species: the fraction of its width a board gains or loses for every 1% change in moisture content, between about 6% and 14%. For okoume they are 0.00212 across a flatsawn face (tangential) and 0.00194 across a quartersawn face (radial).
Worked example: a flatsawn board 7-1/4 in. wide (a nominal 1×8) that goes from 6% moisture content in a heated winter house to 12% in a humid summer changes width by 7.25 × 0.00212 × 6 = 0.092 in. (about 3/32 in.). The same board quartersawn moves 0.084 in. (about 3/32 in.). Allow for this in panels, tabletops and floors; the wood movement calculator works it out for any size and moisture range.
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Okoume | 380 | 24.8* | 7,400 | 1.14 | 6.1 | slightly or nonresistant |
| Yellow-poplar | 540 | 29.4 | 10,100 | 1.58 | 8.2 | slightly or nonresistant |
| Eastern white pine | 380 | 24.5 | 8,600 | 1.24 | 6.1 | moderately resistant (old growth only); otherwise slightly or nonresistant |
| African mahogany (khaya) | 830 | 31.0* | 10,700 | 1.4 | 4.5 | moderately resistant |
| American basswood | 410 | 25.9 | 8,700 | 1.46 | 9.3 | slightly or nonresistant |
| Light red meranti | 460 | 26.0* | 9,500 | 1.23 | 8.5 | slightly or nonresistant |
Uses
In the United States okoume is generally used for decorative plywood panelling, general utility plywood and doors. Other uses include furniture components, joinery and light construction. Outside the Handbook’s list, okoume marine plywood is the standard sheet for small wooden boats, kayaks and canoes, and it is also used for guitar bodies.
Frequently asked questions
How much does okoume plywood weigh?
We estimate solid okoume at about 24.8 lb per cubic foot at 12% moisture content. A 4×8 sheet of 1/4 in. plywood holds about 0.67 cubic feet of wood, so by that density it weighs roughly 16 to 17 lb before the weight of the glue lines; check the maker’s figure for a specific product. Our plywood weight chart shows the method.
Is okoume rot resistant?
No. Its heartwood is nondurable. Okoume boat plywood relies on epoxy, varnish or paint to keep water out.
Is okoume a hardwood?
Botanically yes, it is a broadleaved tree, but it is as soft as many softwoods: 380 lbf of Janka hardness against 380 for eastern white pine.
Okoume vs poplar plywood?
Both are light, even-textured species. In the Handbook data okoume is a little lighter and softer than yellow-poplar; okoume is more common in marine-grade sheets.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 24 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.