Iroko
Milicia excelsa
Also known as African teak, odum, kambala · Botanical Milicia excelsa
Revision history
- — Data re-verified in site-wide audit (formulas, sources, durability classes)
- — Working properties and comparable-species data cross-checked against listed sources
About Iroko
Iroko (Milicia excelsa) is a mid-range timber, hard enough for everyday wear and still easy to work, with a Janka hardness of 1,260 lbf (5,604 N) and a density of about 0.55 g/cm³. It grows in Africa.
Radial 2.8% against tangential 3.8% is an unusually even T/R ratio of 1.36 — Iroko shrinks close to uniformly, which is why it holds a flat panel in exterior joinery and cladding. Its fibre saturation point is near 27%. Below it the wood moves moderately and evenly — 3.8% tangential, 2.8% radial — which is why it machines and stays put as well as it does.8% tangential and a T/R ratio of 1.36, it is one of the steadier timbers to work with.
At 550 kg/m³ a cubic metre of Iroko weighs about 550 kg air-dry — that figure, the 3.8% tangential and 2.8% radial movement and the 1,260 lbf hardness are the three inputs the calculators below actually consume. Select Iroko in any of them to get species-specific results for weight, moisture, shrinkage and hardness.
Working properties
How Iroko behaves at the bench and on the machine, drawn from the CIRAD Tropix tropical-wood database, PROTA and the ITTO tropical-timber service.
Durability & use classification
Iroko heartwood is rated very durable (EN 350 Class 1), resisting fungal decay, termites and dry-wood borers — which is exactly why it is so often used as a lower-cost stand-in for teak. Its natural extractives can, however, corrode ferrous metals in contact, so non-ferrous fixings are wise outdoors.
Typical applications & suitability
Indoor Outdoor — Suited to both interior and demanding exterior work without preservative treatment — its durability and stability make it a genuine outdoor hardwood, not just a decorative one.
Documented end-uses: exterior and structural joinery (beams, frames, flooring, parquet, panelling), furniture and cabinets, boat decks and marine/port work, decorative veneer, cooperage and truck bodies, turned items and musical instruments.
Comparable species
Species closest to Iroko by density, hardness, stiffness and bending strength, computed directly from the Vriksai species dataset rather than hand-picked.
Trade alternatives. Iroko is itself the classic teak substitute (“African teak”). Where it's unavailable, the trade reaches for other durable tropical hardwoods such as Cumaru for exterior work, or African Mahogany for a similar warm tone — matching on durability class first.
Alternatives to Iroko
Iroko measures 1,260 lbf Janka at 0.55 g/cm³, EN 350 durability Class 1, movement rated Excellent. Because Iroko is exterior-rated at Class 1, every candidate below is too. A substitute that quietly drops a durability class is the expensive kind of mistake. Read the numbers against the Janka scale and EN 350 durability classes.
For exterior joinery, cladding and garden work that also has to resist knocks. Harder means more dent resistance but heavier sections and more machining time.
Easier to work and lighter to fix, without dropping below the exterior durability you already have.
Cladding boards and exterior joinery live or die on movement. These give you less of it at equal or better durability. Size the gaps with the shrinkage predictor and EMC calculator.
If Iroko is unavailable and the specification cannot change, these are the nearest substitutes across hardness, density, movement, stiffness, bending strength and durability class together — not on any single property. Lower distance means a closer match.
Computed from measured properties only — hardness, density, movement, stiffness, bending strength and EN 350 class. Price, availability and appearance are never inputs. Figures are representative values, not consignment absolutes: two species within a few percent are equivalent until verified on the material. Full method and the rules the engine cannot break.
Substituting outdoors is a match on durability class and movement first. Colour and grain can be matched later; a wrong durability class shows up as a callback in three monsoons. Where two candidates are close, compare them directly before specifying.
Compare Iroko side by side
These are the head-to-heads that decide cladding, decking and exterior joinery specifications. Every pairing shows the measured figures side by side; full matrix in the comparison index.
Calculators relevant to Iroko
Aimed at exterior detailing in Iroko: coverage, gaps, coating and durability checks. Full set in the tool index.
Understand the figures
Janka hardness scale — how the lbf figure is measured · Wood density reference — oven-dry vs air-dry basis · Moisture content — EMC, FSP and service conditions · Strength properties — MOR, MOE and what they govern.
Further reading. Wood moisture content explained · How to calculate board feet.
Common questions about Iroko
unverified no published source for this figure · FPL USDA FPL Wood Handbook GTR-190 · WD The Wood Database (Eric Meier) · calc derived from the figures above