Teak Wood (Tectona grandis): Properties, Density & Uses

What Teak Is

Teak (Tectona grandis) is a large deciduous hardwood of south and south-east Asia and, together with its close relatives, sits in the family Lamiaceae — the mint family — having been moved there from the older placement in Verbenaceae.3 It carries dozens of regional names: sagwan or segun in the north, thekku in Kerala and Tamil Nadu, kyun in Myanmar, sak in Thailand and jati across the Malay world. In trade it is prized for one quality above all others — the natural durability of its golden-brown heartwood, which needs no chemical treatment to stand up to weather, water and insects.1

Where It Grows

The natural range runs from India through Myanmar, Thailand and Laos, with a naturalised and long-disputed occurrence in Java; Plants of the World Online records the native distribution simply as India to Indo-China.3 Teak is now one of the most extensively planted tropical hardwoods on earth, raised on managed plantations across Africa (Nigeria, Tanzania, Ghana, Ivory Coast), tropical Asia and Latin America (Costa Rica, Brazil, Ecuador).1 As a result, most teak reaching the market today is plantation timber rather than wood cut from natural forest.4

Appearance and Grain

The heartwood ranges from golden to a medium brown and tends to darken with age, sometimes carrying darker streaks; the sapwood is a pale yellow-white and is clearly set apart from the heart.1 Grain is straight to slightly wavy or interlocked, and the texture is coarse and uneven. Freshly milled teak has a somewhat oily or greasy feel and a distinctive leather-like smell — both come from the natural oils and resins concentrated in the heartwood.2 Left outdoors and unfinished, the surface weathers to a silvery grey while the wood beneath stays sound.2

Weight, Density and Strength

Teak is a medium-density hardwood. The Wood Database gives roughly 655 kg/m³ (41 lb/ft³) at 12% moisture, while Wikipedia cites about 660 kg/m³ measured at 15% moisture; both sit inside the usual quoted band of 630–660 kg/m³, so we describe it as about 650 kg/m³.12 Specific gravity is about 0.55 on a basic (oven-dry) basis and near 0.66 measured at 12% moisture. Janka hardness is 1,070 lbf, which the source rounds to about 4,760 N (an exact conversion is closer to 4,760 N); the modulus of rupture is around 97 MPa (14,080 lbf/in²) and the modulus of elasticity about 12.3 GPa (1,781,000 lbf/in²).1 Just as valuable in service is its dimensional stability: shrinkage is low — radial about 2.6%, tangential about 5.3%, giving a T/R ratio near 2.0 — which is a large part of why teak holds its shape through repeated wetting and drying.1

Working, Gluing and Finishing

Teak works reasonably well with both hand and machine tools, but it carries natural silica of roughly 1.4–1.5%, which acts like fine grit and dulls cutting edges quickly; carbide-tipped tooling is therefore preferred.14 The oily heartwood surface can stop adhesives and finishes bonding unless it is wiped with a solvent immediately before work. Because the wood can split, pre-boring before nailing or screwing is advised. Managed properly, teak glues, turns and finishes to a fine surface.1

Durability and Treatment

Teak heartwood is rated very durable: it strongly resists fungal decay and is resistant to termites and to marine borers, which is why it has been the traditional wood for ship and boat decking for centuries.24 This durability is intrinsic, arising from the natural oils and extractives in the heartwood, so no preservative treatment is needed. One caveat matters in practice: only the golden-brown heartwood is durable. The pale sapwood is not, and is prone to attack, so it should be excluded wherever durability is the point.1

Sustainability and Legality

Natural-forest teak is under real pressure and is assessed as Endangered on the IUCN Red List, with a decreasing population trend for wild stands.5 That label reflects the decline of the wild population, not scarcity of commercial timber: teak is one of the most widely planted tropical hardwoods, and the great majority of traded teak now comes from managed plantations across Asia, Africa and Latin America.2 The responsible course is to choose certified or verified plantation teak, which keeps supply both legal and consistent.4

How Cochin Wood Uses Teak

Teak is the yardstick we measure other timbers against. When a customer asks how weather-resistant a species or a panel is, the honest answer is usually framed relative to teak — it is the benchmark durable hardwood of India and South-East Asia, the standard against which weather resistance in timber is judged. That reputation rests on real numbers: a very durable heartwood, low shrinkage and stable behaviour through wet-dry cycling.

For most bulk packing and structural work, teak is not the economical choice — that is where our commercial and Okoume plywood grades earn their place. But where a customer genuinely needs solid decay-resistant hardwood, teak sets the specification, and its performance is the reference point behind our exterior and marine-grade offering. If you are weighing solid timber against a panel product, see our Sawn timber and Marine plywood ranges, or browse the full All species library to compare.