Tembusu


INTRODUCTION

The Standard Malaysian Name for the heavy timber of Fagraea spp. (Loganiaceae). Vernacular names applied include tembusu (Peninsular Malaysia, Sabah and Sarawak) with various epithets, banati (Sabah), meriang (Peninsular Malaysia), temasuk (Sabah) and various other localised names too numerous to be listed here. Major species include F. belukar, F. cuspidata, F. fragrans, F. gigantea, F. resinosa, F. rugulosa, F. spicata, F. teysmannii and F. volubilis. The sapwood is not differentiated from the heartwood, which is light yellow-brown, darkening on exposure to deep golden or orange-brown.

Also known as Kankrao, Tatrao and Trai (Cambodia); Buabua (Fiji); Anrali, Bangkoedoe poete, Kolaki, Nosu, Seranai, Tamosu and Tembesu (Indonesia); Mai man pa (Laos); Anan, Ananma and Burma yellowheart (Myanmar); Dolo, Teca, Tiaong and Urung (Philippines); Keramati (Soloman Islands); Tembusu (Sri Lanka); Kan Krao, Tam-sao and Trai (Thailand); and Trai (Vietnam).


DENSITY

The timber is a Heavy Hardwood with a density of 640-1,075 kg/m3 air dry.


NATURAL DURABILITY

The timber is durable.


PRESERVATIVE TREATMENT

It is difficult to treat with preservatives.


TEXTURE

Texture is fine and even, with straight to slightly wavy grain.


STRENGTH PROPERTIES

The timber falls into Strength Group B (Engku, 1988b) or SG5 (MS 544:Part 2:2001).


MACHINING PROPERTIES

It is easy to resaw and cross-cut. Planing is easy and the planed surface is smooth.


NAILING PROPERTY

The nailing property is rated as good.


AIR DRYING

The timber seasons extremely slowly, with only slight end-checking and surface–splitting as the main sources of degrade. 13 mm thick boards take approximately 5 months to air dry, while 38 mm thick boards take 16 months.


SHRINKAGE

Shrinkage is fairly low, with radial shrinkage averaging 1.1% and tangential shrinkage averaging 1.6%.


USES

The timber is suitable for heavy construction, marine construction, posts, beams, joists, rafters, tool handles (impact), pallets (permanent heavy duty type), door and window frames and sills, cooling tower (structural members), telegraphic and power transmission posts, bridges, flooring (heavy traffic), panelling, mouldings and heavy duty furniture. It has an excellent reputation as a carving timber.


REFERENCES

  1. Engku Abdul Rahman Chik. 1988b. Basic And Grade Stresses For Some Malaysian Timbers. Malayan Forest Service Trade Leaflet No. 38. The Malaysian Timber Industry Board And Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
  2. Menon, P. K. B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S. C. Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and Forest Research Insitute Malaysia, Kuala Lumpur. 48 pp.
  3. MS 544: Part 2: 2001: Code Of Practice For Structural Use Of Timber. Permissible Stress Design of Solid Timber.
  4. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Record No. 30. Forest Research Institute Malaysia Kuala Lumpur. 201 pp.