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Blunting Effect Boring Carving Comments Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Light-Induced Color Change Luster Mortising Movement in Service Nailing Natural Durability Natural Growth Defects Numerical Data Odor Planing Polishing References Regions of Distribution Resistance to Impregnation Response to Hand Tools Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Texture Trade Name Tree Identification Tree Size Turning		Scientific Name Alstonia congensis Trade Name Emien Family Name Apocynaceae Common Names Adawera, Adawra, Ahun, Alstonia, Awen, Bakunin, Bantang foro, Basong, Binu, Bokuk, Bokuka, Cheese wood, Dita, Dnyame-dua, Dsen-nuru, Duku, Ebo, Ebwe, Ekouk, Emee, Emenle, Emien, Kaiwi, Kanja, Kauwi, Kigima, Koloweli, Kuge, Lomba, Mergalang, Milkwood, Milky pine, Mo cua, Mogoliga, Mogvga, Mujua, Mujwa, Mukoge, Musoga, N'songuti, Nsiwa, Nyamelebaka, Nyemidua, Omujwe, Onguie, Patternwood, Pulai, Senedur, Shaitan wood, Sindru, Stolwood, Stoolwood, Sundra, Tsongoti, Tsongutti, Uguwa, Vhu, White cheesewood, Wokuka, Yung Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Benin, Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon, Ghana, Ivory Coast, Liberia, Nigeria, Sierra Leone, Tanzania, Uganda, Zaire Common Uses Agricultural implements, Baskets, Bent Parts, Boat building (general), Boxes and crates, Cabinetmaking, Carvings, Chairs, Chemical derivatives, Chests, Core Stock, Desks, Dining-room furniture, Drawer sides, Excelsior, Fine furniture, Food containers, Furniture , Furniture components, Furniture squares or stock, Furniture, General carpentry, Hatracks, Joinery, Kitchen cabinets, Light construction, Living-room suites, Matchboxes, Matches, Millwork, Moldings, Musical instruments, Musical instruments: percussion, Musical instruments: strings, Office furniture, Packing cases, Particleboard, Plywood corestock, Plywood, Pulp/Paper products, Radio - stereo - TV cabinets, Rustic furniture, Stools, Toys, Turnery, Utility furniture, Veneer, Veneer: decorative, Wardrobes, Woodwork Environmental Profile Endangered Abundant/Secure Generally secure within most of its natural habitat, but note exceptions. Endangered in Benin. Inadequate info in Angola, Equatorial Guinea, and Nigeria Distribution Overview Widely distributed throughout West and Central Africa; abundant in humid forests of the Cameroons. Heartwood Color White Yellow Orange Brown Red Green/grey Yellow to golden-yellow to orange White to cream Pale brown Yellowish white Greenish to greyish Brown Sapwood Color White Yellow Brown Red Color not distinct from heartwood White to yellow Grain Straight Closed Even Wavy Interlocked Generally straight, but not always Wavy Interlocked Texture Fine Medium Fine to medium Fine Medium Luster Low Medium Lustrous Low Dull Natural Growth Defects Latex or other ducts Natural Durability Susceptible to insect attack Perishable Non-resistant to termites Non-resistant to powder post beetles Non-durable Non-resistant to marine borers Perishable Susceptible to wood staining fungal attack Susceptible to attack from termites (Isoptera) Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Non durable Susceptible to marine borer attack Vulnerable to attack by powder-post beetles Odor No specific smell or taste Light-Induced Color Change Darker Kiln Schedules Drying (speed) is fast Uk=H US=T10D4S/T8D3S Fr=7 T10 - D4S (4/4); T8 - D3S (8/4) US Schedule H; United Kingdom Kiln Drying Rate (in days) is fairly rapid Drying Defects Checking Distortion Splitting Slight surface checking Slight end splitting Slight twist/warp No twisting or warping No surface checking Ease of Drying Fairly Easy Rapidly Reconditioning Treatement Little degrade Easy Little degrade if dried properly Kiln Drying Rate Naturally dries quickly Rapid Drying rate is fairly rapid to fast Rapid (<10 days for boards < 32 mm, to <30 days for boards >= 63 mm) Tree Identification Bole/stem form is buttressed Bole/stem form is fluted Bole/stem form is cylindrical Bole/stem form is misshapen Tree Size Trunk diameter is 100-150 cm Tree height is 30-40 m Tree height is 40-50 m Bole length is 20-30 m Tree height is 20-30 m Comments General finishing qualities are rated as satisfactory Latex Content - Large slit-like radial canals, which are usually found at intervals of 1 to 3 feet (30 to 90 cm) and which may adversely affect the appearance of the wood usually contain traces of latex. Latex is reported to remain in liquid form for long periods of time and may even be detected in sawing wood that was processed years ago. Blunting Effect Little Moderate Blunting effect on sawing dry wood is mild Blunting effect on machining is slight There is some significant blunting effect on cutting tools Boring Fairly easy to very easy Fair to good results Moderately easy Carving Very Good to Excellent Results Very good results Cutting Resistance Easy to saw Cutting Resistance with dry wood is easy Cutting edges are dulled rapidly Gluing Fairly Easy to Very Easy Fair to Good Results Fairly Difficult to Very Difficult Easy to glue Moderate gluing properties Glues well Mortising Fair to Good Results Fairly Easy to Very Easy Finishes satisfactorily Movement in Service Excellent Stability - Small Movement Fair to Good Stability - Medium Movement Small Stable Nailing Fairly Easy to Very Easy Fair to Good Results Pre-Boring Recommended Very Good to Excellent Results Easy to nail Satisfactory nailing properties Pre-boring recommended Holds satisfactorily Holds nails well Planing Fairly Easy to Very Easy Fair to Good Results Easy to plane Sharp surfaces are required Resistance to Impregnation Permeable heartwood Permeable sapwood Heartwood is permeable Sapwood is permeable Response to Hand Tools Easy to Work Responds Readily Easy to machine Responds well to hand tools Screwing Fairly Easy to Very Easy Fair to Good Results Pre-boring recommended Easy to screw Screwing yields satisfactory results Recommend pre-boring Possible if prebored Good screw holding properties Turning Fair to Good Results Fairly Easy to Very Easy Satisfactory Steam Bending Poor to Very Poor Results Unsuitable Poor Polishing Fair to Good Results Very Good to Excellent Results Good results Staining Fair to Good Results Very Good to Excellent Results Finish is generally satisfactory Finish is generally good Stains well Strength Properties Density (dry weight) = 23-30 lbs/cu. ft. Bending strength (MOR) = low Hardness (side grain) = very soft Max. crushing strength = medium Max. crushing strength = low Shrinkage, Radial = small Shearing strength (parallel to grain) = very low Shrinkage, Tangential = small Shrinkage, Tangential = fairly large Bending strength (MOR) = very low Shrinkage, Radial = fairly large Density (dry weight) = 15-22 lbs/cu. ft. Shrinkage, Volumetric = small Shrinkage, Volumetric = moderate Shrinkage, Tangential = moderate Shrinkage, Radial = moderate Max. crushing strength = high Hardness (side grain) = soft Density (dry weight) = 31-37 lbs/cu. ft. Bending strength (MOR) = medium Numerical Data Item Green Dry English Bending Strength 5382 8221 psi Density 25 lbs/ft3 Hardness 367 lbs Impact Strength 16 15 inches Maximum Crushing Strength 2950 4789 psi Shearing Strength 930 psi Stiffness 1007 1147 1000 psi Work to Maximum Load 5 7 inch-lbs/in3 Specific Gravity 0.26 Weight 25 25 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 6 % Volumetric Shrinkage 10 % Item Green Dry Metric Bending Strength 378 578 kg/cm2 Density 400 kg/m3 Hardness 166 kg Impact Strength 40 38 cm Maximum Crushing Strength 207 336 kg/cm2 Shearing Strength 65 kg/cm2 Stiffness 70 80 1000 kg/cm2 Work to Maximum Load 0.35 0.49 cm-kg/cm3 Specific Gravity 0.26 Weight 400 400 kg/m3 Radial Shrinkage 4 % Tangential Shrinkage 6 % References Bertin, A., Meniaud, J.,1949,Timbers of the Cameroons,Compagnie Francais du Cameroon,(Transl. by F.Jane) Bois et Forets des Tropiques,1954,Emien,Bois et Forets Tropiques,38,pp22-6 Bolza, E., Keating, W.G.,1972,African Timbers - the Properties, Uses and Characteristics of 700 Species,C.S.I.R.O. Div. of Building Research Brown, W.H.,1969,Properties and uses of Tropical hardwoods in the United Kingdom. Part 1,Nonstructural properties and uses.,Conference on Tropical hardwoods SC-5/TN-5, Syracuse University Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. Clifford, N.,1953,Commercial Hardwoods - Their Characteristics Identification and,Utilization,Sir Isaac Pitman & Sons Ltd. London Dalziel, J.M.,1937,The Useful Plants of West Tropical Africa,Crown Agents for the Colonies Eggeling, W.J., Harris, C.M.,1939,Fifteen Uganda Timbers,Forest Trees and Timbers of the British Empire, Imperial Forestry,Institute, Oxford,Part 4 Eggeling, W.J.,1940,Indigenous Trees of Uganda,Govt. Printer Entebbe Uganda Erfurth, T., Rusche, H.,1976,The Marketing of Tropical Wood A. Wood Species from African Moist Forests,F.A.O. Forestry Department Farmer, R.H.,1972,Handbook of Hardwoods,HMSO Forest Products Research Laboratory, Nigeria,1965,Nigerian Timbers for Matchmaking,Nigeria Fed. Department of Forest Research, Ibadan, Forest Products,Research Laboratory Report No.5 Forest Products Research Laboratory, U.K.,1933,Preliminary Tests on Timbers investigated under the Auspices of the E.T.C.,Forest Products Research Laboratory, Princes Risborough,, Project 22 Inv.,15 + Addendum Forest Products Research Laboratory, U.K.,1950,The Seasoning Properties of Exotic Timbers,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research Leaflet,No.44 and supplements 1 & 2 Forest Products Research Laboratory, U.K.,1955,Kiln-Drying Schedules,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment Leaflet,No.42 Fouarge, J., Gerard, G.,1964,Bois du Mayumbe,I.N.E.A.C. Belguim Fouarge, J.,1970,Essais Physiques,Mecaniques et de Durabilite de Bois de la Republique,Democratique du Congo,I.N.E.A.C. Belgium Serie Technique,No.76 France - C.T.F.T./C.T.B.,1982,Guide pour le Choix des Essences Deroulables-pour la fabrication du,contreplaque,C.T.F.T./C.T.B. France France - C.T.F.T.,Promotion of Cameroon Timbers. New Series (Leaflets,C.T.F.T. Ghana - Timber Marketing Board,1969,Ghana Hardwoods,Timber Marketing Board Gutierrez Oliva, A., Plaza Pulgar, F.,1967,Caracteristicas fisico-mecanicas de las maderas Espanolas. (Physical and,mechanical properties of Spanish timbers.,Min.Agric./Dir.Gen Montes/Instituto Forestral de Investigaciones,y,Experiencias, Madrid pp102 HMSO. 1981. Handbook of Hardwoods, 2nd Edition. Revised by R. H. Farmer. Department of the Environment, Building Research Establishment, Princes Risborough Laboratory, Princes Risborough, Aylesbury, Buckinghamshire. Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London ITTO. 1986. Tropical Timber Atlas, Volume 1 - Africa. International Tropical Timber Organization (ITTO) and Centre Technique Forestier Tropical (CTFT, 45bis, Avenue de la Belle Gabrielle, Nogent-sur-Marne Cedex, France. Jay, B.A.,1968,Timbers of West Africa,TRADA, Red Booklet Series Kinloch, D., Miller, W.A.,1949,Gold Coast Timbers,Govt. Printer Gold Coast Kloot, N. H. and E. Bolza. 1961. Properties of Timbers Imported into Australia. Technological Paper No. 12. Division of Forest Products, Commonwealth Scientific and Industrial Research Organization, Melbourne, Australia. Kloot, N.H., Bolza, E.,1961,Properties of Timbers Imported into Australia,C.S.I.R.O. Forest Products Division Technological Paper,No.12 Kryn, J.M., Forbes, E.W.,1959,The Woods of Liberia,U.S.A. Department of Agriculture,Forest Products Laboratory, Madison,,Report No. 2159 Kukachka, B.F.,1970,Properties of Imported Tropical Woods,Forest Research Paper FPL 125 Lavers, G. M. 1966. The Strength Properties of Timbers. Forest Products Research Bulletin, No. 50. Ministry of Technology, Her Majesty's Stationery Office, London. Lavers, G.M.,1983,The Strength Properties of Timber (3rd ed. revised Moore G.L.,Forest Products Research Laboratory, Princes Risborough, Building Research,Establishment Report (formerly Bulletin No.50) Patterson, D.,1988,Commercial Timbers of the World, 5th Edition,Gower Technical Press Pieters, A.,1977,Essences Forestieres du Zaire,R.U.G. Gent Belguim Sallenave, P.,1955,Proprietes Phyiques et Mecaniques des Bois Tropicaux de l'Union Francaise,C.T.F.T Scott, M.H.,1950,Notes on the more Important African Timbers Imported into the Union with,Special Ref. to Port. E.A. Species,Journal of the South African Forestry Association,No.19,pp18-62,[South,African Forestry Journal] Scott, M.H.,1953,Utilisation Notes on South African Timbers,South African Forestry Department Bulletin No.36 Spalt, H.A., Stern, W.L.,1956,Survey of African woods 1,Tropical Woods,115(105,pp 13-38 Tack, C.H.,1969,Uganda Timbers,Govt. Printer Uganda Takahashi, A.,1978,Compilation of Data on the Mechanical Properties of Foreign Woods (Part,III) Africa,Shimane University, Japan, Research Report on Foreign Wood No. 7 Timber Development Association,1948,Some New Timbers and Their Uses No. 34,Timber Development Association Limited, London [TRADA] Timber Information Assoc. Ltd.,1947,Notes on East African Timbers,TRADA, Timber Information, No.28 Uganda Forest Department,1954,Alstonia,Uganda Forestry Department Timber Leaflet,No.2 Uganda Forest Department,1954,The Mechanical Properties of some Ugandan Timbers,Uganda Forest Department Timber Leaflet,No.1 Uganda Forest Department,1969,The Shrinkage of Some Ugandan Timbers,Uganda Forestry Department Timber Leaflet,No.47 United Kingdom - H.M.S.O.,1954,Report of the Matchwood Working Party,H.M.S.O. for the Board of Trade and Ministry of Materials Unwin, A.H.,1920,West African Forests and Forestry,T. Fisher Unwin Ltd. London WCMC. 1992. Conservation Status Listing - Trees and Timbers of the World. World Conservation Monitoring Center-Plants Programme, Cambridge, CB3 ODL, United Kingdom.