Narra Wood

Narra is a large deciduous tree of up to 30 to 40 m tall and 2 m in diameter. It has a dense, wide spreading, dome-shaped crown with drooping lower branches. The trunk is buttressed and the bark is smooth and grey-brown, becoming scaly and fissured with age. When cut or slashed, dark red resin oozes out. The wood varies in colour from light yellow to golden brown to reddish brown, and has a camphor or cedar scent.

SCIENTIFIC INFORMATION Botanical name: Pterocarpus Indicus Common Name: Amboyna, Andaman padauk, Andaman redwood, Angsama, Angsana, Chalanga-da, East Indian mahogany, Indian redwood, Liki, Nara, Narra, Narravitail, New Guinea rosewood, Nonalu, Padauk, Papua New Guniea rosewood, Red narra, Ringii, Rosewood. Also known as Sonokembang  or Amboyna Padauk. Distribution: Southeast Asia and Pacific Geography It is widely distributed in Southeast Asia and is popular worldwide, planted in countries such as Africa, India, Sri Lanka, Taiwan and Okinawa, Hawaii and Central America. In its natural habitat, it grows on flat coastal plains behind mangrove swamps, or along inland rivers in forests where the dry season is not pronounced. Description The Sonokembang is a large deciduous tree of up to 30 to 40 m tall and 2 m in diameter. It has a dense, wide spreading, dome-shaped crown with drooping lower branches. The trunk is buttressed and the bark is smooth and grey-brown, becoming scaly and fissured with age. When cut or slashed, dark red resin oozes out. The wood varies in colour from light yellow to golden brown to reddish brown, and has a camphor or cedar scent. DENSITY The timber is moderately hard and moderately heavy with a density of 560-690 kg/m3 air dry. NATURAL DURABILITY Sena is moderately durable. Its sapwood is readily attacked by fungi and insects. PRESERVATIVE TREATMENT Sena is very easy to treat with preservatives. TEXTURE Texture is moderately coarse and uneven, due to the ring-porous structure. Grain is interlocked and sometimes wavy. STRENGTH PROPERTIES The timber falls into Strength Group C (Burgess, 1958).  Strength Properties of Sena Test Condition Compression parallel to grain (MPa) Compression perpendicular to grain (MPa)  Side hardness(N) Shear parallel to grain (MPa) Green 31.2 6.14 4,540 9.0 MACHINING PROPERTIES It is slightly difficult to resaw and cross-cut due to the presence of severely interlocked grain. Planing is easy but the finish is only moderately smooth with some grain pick-up in radial sawn material. Machining Properties of Sena Test condition Sawing Planing Boring Turning Re-sawing Cross- cutting Ease of planing Quality of finish Ease of boring Quality of finish Ease of turning Quality of finish Green slightly difficult easy easy tangential: smooth; radial: rough due to grain pick-up moderately easy smooth - - Air dry slightly difficult slightly difficult easy moderately smooth slightly difficult smooth moderately easy smooth smooth AIR DRYING The timber seasons fairly slowly, with very little degrade, except for some insect and fungal attacks on the sapwood. 13 mm thick boards take approximately 4 months to air dry and 38 mm thick boards take 5 months. SHRINKAGE Shrinkage is low, with radial shrinkage averaging 0.9% and tangential shrinkage averaging 1%. DEFECTS The logs are generally free from natural defects. COMMON USES The timber is one of the rare ring-porous timbers found in this country and as such is highly prized as a cabinet wood. The timber is suitable for all forms of decorative works, joinery, interior finishing, panelling, mouldings, high class furniture, plywood, flooring, staircase (apron lining, baluster, handrail, newel and sprandrel framing) and ornamental items.