Azobe (Ekki)

Azobe (Lophira alata), sold in Europe as Ekki and in Germany as Bongossi, is one of the heaviest and most durable timbers of West and Central Africa. It is cut from a large evergreen tree of the family Ochnaceae found through the coastal and lowland rainforest belt from Sierra Leone to the Congo Basin.

At a glance it is a very dense, dark reddish-brown to chocolate-brown wood with a fine, straight-to-interlocked grain and a coarse texture — matching our sample. Its defining traits are extreme weight and hardness, high silica content, and exceptional resistance to decay and marine borers, which is why it is a first-choice timber for harbor works, bridges, and heavy-duty decking rather than fine furniture.

The heartwood is dark reddish-brown to deep chocolate-brown, frequently marked with pale, whitish specks and streaks where silica and gum fill the vessels; it darkens further on exposure. The sapwood is clearly distinct, pale pinkish to lighter brown. Grain runs fine and straight to moderately interlocked, the texture is coarse but even, and the luster is low.

Azobe is an ironwood in the literal sense — air-dry density is roughly 1,000–1,100 kg/m³, so freshly cut or wet stock will often sink in water. Its Janka hardness is about 3,350 lbf, placing it among the hardest commercial timbers, far above white oak and comparable to the densest tropical ironwoods.

The heartwood is rated very durable (durability class 1), with excellent resistance to fungal decay, termites, and — importantly — marine borers such as Teredo, which is the basis for its use in permanent seawater structures. The pale sapwood is not durable and is liable to insect attack. The wood is strong in bending and compression but is difficult to season, drying slowly with a marked tendency to check, split, and distort.

Azobe is a heavy-construction and marine timber above all. Typical uses include harbor and dock works, marine and river piling, lock gates, fenders, groynes, jetties, and other hydraulic structures where contact with salt or fresh water is constant.

On land it is used for heavy-duty decking and boardwalks, bridge decking and beams, railway sleepers, mine timbers, cooling-tower components, industrial and factory flooring, and heavy framing. Its extreme hardness and durability suit it wherever abrasion, load, and rot resistance outweigh workability or appearance; it is rarely chosen for furniture or joinery.

Azobe is difficult to work by both hand and machine. Its density and appreciable silica content blunt cutting edges very quickly, so stellite-tipped or tungsten-carbide tooling is essentially mandatory, and sawing generates heavy resistance. The interlocked grain can tear on machined faces, and the wood is hard to plane to a smooth finish.

Nailing and screwing require pre-boring without exception — the wood will split and fasteners will not drive otherwise. Gluing is unreliable because of the dense, sometimes gummy surface, so mechanical fastening is preferred; where bonding is needed, freshly machined surfaces and suitable adhesives are essential. It is seldom finished decoratively, but it can be brought to a serviceable surface with sharp tooling.

Cautions: Azobe dust is a recognized irritant and can cause skin, eye, and respiratory irritation, so effective dust extraction and a respirator are advised. The wood contains extractives that can corrode ferrous metals and cause dark staining in damp conditions, so non-ferrous or galvanized fixings are recommended. It is not a CITES-listed species, but standard fine-dust precautions apply.

Azobe/Ekki is a specialty imported hardwood supplied mainly as heavy structural sections, piling, decking, and marine timbers through civil-engineering and hardwood importers rather than general lumberyards. It sits in the mid price band for African hardwoods — the cost is driven less by the timber itself than by the large, heavy sections it is typically sold in and the machining difficulty. Availability is steady but oriented to construction and marine buyers.

Lophira alata is not listed under CITES, so there are no CITES permit requirements. However, it is assessed as Vulnerable on the IUCN Red List owing to habitat loss and exploitation across its range, so responsibly sourced or FSC-certified material is preferable where available.