IROKO timber GUIDE
Scientific Name: Milicia excelsa, M. regia (syn. Chlorophora excelsa, C. regia)
Distribution: Tropical Africa
Tree Size: 100-130 ft (30-40 m) tall, 3-5 ft (1-1.5 m) trunk diameter
Average Dried Weight: 41 lbs/ft3 (660 kg/m3)
Specific Gravity (Basic, 12% MC): .55, .66
Janka Hardness: 1,260 lbf (5,610 N)
Modulus of Rupture: 12,700 lbf/in2 (87.6 MPa)
Elastic Modulus: 1,360,000 lbf/in2 (9.38 GPa)
Crushing Strength: 7,840 lbf/in2 (54.0 MPa)
Shrinkage: Radial: 2.8%, Tangential: 3.8%, Volumetric: 8.8%, T/R Ratio: 1.4
Color/Appearance: Heartwood is usually a yellow to golden or medium brown, with color tending to darken over time. Pale yellow sapwood is clearly demarcated from the heartwood.
Grain/Texture: Iroko has a medium to coarse texture, with open pores and an interlocked grain.
Endgrain: Diffuse-porous; large pores in no specific arrangement; solitary and radial multiples of 2-3; tyloses common; growth rings indistinct; rays visible without lens; parenchyma banded, paratracheal parenchyma vasicentric, aliform (winged and lozenge), and confluent.
Rot Resistance: Iroko is very durable, and is resistant to both rot and insect attack; it’s sometimes used as a substitute for Teak.
Workability: Generally easy to work, with the exception of its interlocked grain, which may cause some tearout during surfacing operations. Also, deposits of calcium carbonate are sometimes present, which can have a significant dulling effect on cutters. Iroko glues and finishes well.
Odor: No characteristic odor.
Allergies/Toxicity: Although severe reactions are quite uncommon, Iroko has been reported as a sensitizer. Usually most common reactions simply include eye, skin, and respiratory irritation. Iroko can also cause other health effects in sensitive individuals, such as asthma-like symptoms, boils, and hypersensitivity pneumonitis. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.
Pricing/Availability: Iroko is imported and available for a moderate price.
Sustainability: This wood species is not listed in the CITES Appendices, but is on the IUCN Red List. It is listed as vulnerable due to a population reduction of over 20% in the past three generations, caused by a decline in its natural range, and exploitation.
Common Uses: Veneer, flooring, furniture, cabinetry, boatbuilding, turned items, and other small specialty wood items.
Comments: Given the high prices of genuine Teak, Iroko could be considered a low-cost alternative. The wood is stable, durable, and has an overall look that somewhat resembles Teak.