TIAMA (Entandrophragma excelsum)
Trade Name
Tiama
Scientific Name
Entandrophragma excelsum Sprague
Family
MELIACEAE
Common Names
Gedur-nohor (Nigeria); Edinam (Ghana); Tiama (Côte d`Ivoire); Umuyoke (Burkina Faso); Gedur-nohor (United Kingdom); Tiama-mahagoni (Germany); Acuminata (Germany); M'vovo (Zaire); Lifaki (Zaire); Abeubegne (Gabon); Dongomanguila (Equatorial Guinea); Kiluka (Congo); Mukusu (Uganda); Livuite (Angola); Acuminata (Angola); Tiama
Scientific Name Synonyms
Entandrophragma speciosum Harms in Mildbr.
Description Of The Tree
Botanical Description
The tree may reach a height of 45 m, with a trunk diameter up to 130 cm. The bole is up to 26 m in length. The buttresses are generally strongly developed and extending up to 5 m.
Natural Habitat
Entandrophragma excelsum is chiefly found in montane forests.
Wood Identification
Anatomic Description Of Wood
Wood diffuse porous. Occasionally vessels exclusively solitary (over 90%). Tangential diameter of vessel lumina 150 to 200 micras (medium). Brown-colored deposits in heartwood vessels. Non-vestured pits. Vessels per mm2 less than 6 (rare). Simple perforation pl Axial parenchyma in marginal or in seemingly marginal bands. Axial parenchyma confluent unilateral paratracheal. Occasionally prismatic crystals in non-chambered axial parenchyma cells. 5 to 8 cells per parenchyma strand. 4 to 10 rays per mm (medium). Rays non-storied. Larger rays more than 4 seriate. Body ray cells procumbent with one row of upright and/or square marginal cells (Kribs-III). Septate fibers present. Fibers with simple to minutely bordered pits.
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Wood Macro Photo Radial Plane
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Wood Micro Photo Of Transversal Section
Availability
Cites Status
Unrestricted
General Wood Description
Color
The sapwood is whitish or pinkish, it has a thickness of 10 cm. The heartwood is red-brown, darkening slightly on exposure, it is clearly demarcated. The silver figure is fine.
COLOR INDEX (1=Black, 7=Light yellow,white)
4
Grain
Straight or slightly interlocked, sometimes with an influence on further processing operations.
Texture
The wood is reported to be frequently medium textured.
Luster
It is reported to be low in luster.
Natural Durability
Slightly durable to decay. This species needs preservative treatment for uses with risks of occasional re-humidification. It is not suited for uses with risks of permanent or long-lasting humidification. Sensible to termites attack. The heartwood is resistant
Natural durability index (1= Very high durability, 7=Vey low durability)
6
Internal Growth Stresses
Residual growth stresses are absent.
Resistance To Impregnation
Nearly impossible to treat with a too much low penetration of the preservative substances.
Wood Physical Properties
Basic Density or Specific Gravity (O.D. weight/vol. green) (g/cm³)
0.46
Air-dry Density (Weight and volume at 12%MC) (g/cm³)
0.50
Total shrinkage Tangential (Saturated to 0%MC) (%)
9.5
Total shrinkage Radial (Saturated to 0%MC) (%)
4.3
Drying Defects
Ease of Drying: The timber seasons moderately slowly with slight degrade. Boards of 15 mm thick take about 3.5 months to air dry. Kiln Schedules: Schedule proposed for Keledang.
Recommended Dry Kiln Schedule
FR-9
Dimensional stability ratio (Total Tangential Shrinkage %/Total Radial Shrinkage %)
2.2
Wood Chemical Properties
Wood Mechanical Properties
Bending Strength (MOR),12%MC (kgf/cm²)
701
Stiffness (MOE) 12%MC (kgf/cm²)
104159
Compression parallel to fiber 12%MC (kgf/cm²)
428
Compression perpendicular to fiber 12%MC (kgf/cm²)
50
Shear strength radial 12%MC (kgf/cm²)
41
Janka hardness (side) 12%MC (kgf)
301
Janka hardness (end grain) 12%MC (kgf)
403
Workability
Sawing
It is easy to saw.
Rotary Veneer Cutting
Suitable for slicing, also suitable for peeling if treated.
Sliced Veneer
Suitable for slicing, also suitable for peeling if treated.
Blunting Effect
Slight blunting effect; ordinary tools can be used for sawing and machining.
Machining
Possible difficulties caused by interlocked grain are reported.
Planing
Easy; no particular problems.
Moulding
Rather difficult; special tools are needed.
Turning
30
Boring
Rather difficult; special tools are needed.
Mortising
Rather difficult; special tools are needed.
Nailing
No particular problem.
Gluing
Glues well if basic gluing technical rules are followed.
Sanding
Easy to perform; it gives good results.
Polishing
Can be polished without surface preparation.
Steam Bending
This species can be used for steam bending.
Response To Hand Tools
No particular problems.
REFERENCED USES
End Uses Summary
HOUSING GENERAL, beams, joists, boards, flooring, parquet, frames, steps, panelling, fittings, FURNITURE AND CABINETS, luxury furniture, cabinets, PLYWOOD AND VENEER, faces, Decorative veneer, TURNING, ornaments, turned furniture, NAVAL CONSTRUCTION, boat deck, port storage
General Housing
- 10 - Silica in Timbers
Beams
- 11 - Prospect: The wood database
Joists
- 12 - Tropical timbers of the world. Part I-Tropical American Species
Boards
- 13 - Dry kiln schedules for commercial woods. Temperate and tropical. Section III. Latin American (Mexico, Central, and South America) Woods–Conventional Temperatures
Flooring
- 14 - Handbook of Hardwoods
Parquet
- 15 - Empire Timbers
Frames
- 16 - Woods of the World
Steps
- 17 - Tree Conservation Database
Paneling
- 18 - W3TROPICOS Missouri Botanical Garden
Fittings
- 19 - Silica in Timbers
Furniture Cabinets
- 21 - Tropical timbers of the world. Part III-Southeast Asian and Oceanian Species.
Furniture, Luxury
- 22 - Dry kiln schedules for commercial woods. Temperate and tropical. Section IV-Asian and Oceanian Woods
Cabinet
- 24 - Empire Timbers
Panels, Veneers
- 25 - Directory of Timber Trade Malaysia
Faces
- 26 - Annual Review and Assessment of the World Timber Situation 1998-ITTO
Decorative veneer
- 28 - Ministry of Agriculture, Fisheries & Forest of Fiji
Turning
- 30 - Embassy of Honduras in Japan
Ornaments
- 31 - Embassy of Colombia in Japan
Turned Articles
- 32 - Embassy of Cote d`Ivoire in Japan
Shipbuilding
- 55 - Tropical Timber Atlas of Latin America
Boat Decking
- 59 - Programa Nacional de uso Sostenible de los Bosques e Incremento a las Exportaciones.
Port Storage
- 62 - Estudio Tecnológico de Maderas del Perú (Zona Pucallpa) Vol I
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