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Comments Common Names Common Uses Countries of Distribution Cutting Resistance Drying Defects Ease of Drying Family Name Gluing Grain Heartwood Color Kiln Schedules Luster Nailing Natural Durability Numerical Data Painting Planing Polishing References Regions of Distribution Resistance to Impregnation Response to Hand Tools Sapwood Color Scientific Name Screwing Strength Properties Texture Trade Name Tree Identification Tree Size Turning Varnishing Scientific Name Coula edulis Trade Name African walnut Family Name Olacaceae Common Names African walnut, Akion, Almond wood, Atsan, Attia, Bodwe, Bogue, Coula, Ebo, Ewome, Ewoumeu, Gabon nut, Kumunu-kumunu, Nkula, Okolla, Sra, Srah Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Cameroon, Congo, Gabon, Ivory Coast, Liberia, Sierra Leone Common Uses Agricultural implements, Boat building (general), Carvings, Charcoal, Flooring, Furniture, Heavy construction, Joinery, Light construction, Millwork, Mine timbers, Musical instruments, Plywood, Poles, Posts, Railroad ties, Sporting Goods, Tool handles, Turnery, Vehicle parts Heartwood Color Brown Green/grey Red Purple Reddish brown Sapwood Color Brown White to yellow Well defined Different than heartwood Grain Straight Closed Interlocked Even Weak (figure) Figure Wavy Straight Interlocked Weak figure Weak figure Wavy Texture Fine Fine Medium Fine to medium Luster Dull Natural Durability Very durable Durable Susceptible to insect attack Resistant to marine borers Resistant to termites Non-resistant to powder post beetles Resistant to powder post beetles Resistant to attack from termites (Isoptera) Resistant to attack from powder post (Lyctid & Bostrychid) beetles Moderately resistant to marine borer attack Heartwood is fairly resistant to termites and other insects Very durable Durable Kiln Schedules Drying (speed) is fast Drying Defects Splitting Ease of Drying Moderately Difficult to Difficult Slowly Easy Tree Identification Bole/stem form is not buttressed Bole/stem form is buttressed Tree Size Tree height is 20-30 m Tree height is 10-20 m Tree height is 0-10 m Trunk diameter is 200-250 cm Comments General finishing qualities are rated as good Cutting Resistance Easy to saw Cutting Resistance with dry wood is easy Gluing Fairly Easy to Very Easy Nailing Pre-Boring Recommended Difficult to nail Planing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Difficult to plane Resistance to Impregnation Resistant sapwood Resistant heartwood Heartwood is extremely resistant Response to Hand Tools Easy to Work Easy to machine Screwing Pre-boring recommended Turning Fairly Easy to Very Easy Painting Good results Polishing Fair to Good Results Very Good to Excellent Results Satisfactory results Varnishing Very Good to Excellent Results Fair to Good Results Fairly Easy to Very Easy Good results Strength Properties Shrinkage, Tangential = fairly large Max. crushing strength = high Bending strength (MOR) = very high Bending strength (MOR) = high Shrinkage, Volumetric = fairly large Shrinkage, Radial = moderate Shrinkage, Radial = fairly large Shrinkage, Volumetric = moderate Shrinkage, Tangential = large Hardness (side grain) = hard Shrinkage, Tangential = very small Shrinkage, Radial = very small Shearing strength (parallel to grain) = medium Shearing strength (parallel to grain) = high Modulus of Elasticity (stiffness) = medium Modulus of Elasticity (stiffness) = high Max. crushing strength = very high Shrinkage, Tangential = small Shrinkage, Radial = small Modulus of Elasticity (stiffness) = very high Hardness (side grain) = very hard Hardness (side grain) = medium Density (dry weight) = 61-67 lbs/cu. ft Density (dry weight) = 53-60 lbs/cu. ft Bending strength (MOR) = medium Numerical Data Item Green Dry English Bending Strength 16521 24154 psi Density 60 lbs/ft3 Hardness 2310 lbs Maximum Crushing Strength 7795 10986 psi Shearing Strength 2525 psi Stiffness 2048 2369 1000 psi Weight 59 48 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 8 % Volumetric Shrinkage 12 % Item Green Dry Metric Bending Strength 1161 1698 kg/cm2 Density 961 kg/m3 Hardness 1047 kg Maximum Crushing Strength 548 772 kg/cm2 Shearing Strength 177 kg/cm2 Stiffness 143 166 1000 kg/cm2 Weight 945 769 kg/m3 Radial Shrinkage 4 % Tangential Shrinkage 8 % References 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 Cooper, G.P., Record, S.J.,1931,The Evergreen Forests of Liberia,Yale School Forestry Bulletin,31,pp1-153 Erfurth, T., Rusche, H.,1976,The Marketing of Tropical Wood A. Wood Species from African Moist Forests,F.A.O. Forestry Department Fortin, Y., Poliquin, J.,1976,Natural Durability and Preservation of 100 Tropical African Woods,International Development Research Centre, Canada Fougerousse, M., Deschamps, P.,1968,Essais de Resistance de quelques Bois Tropicaux aux Xylophages Marins dans,la,Port de la Pallice,C.T.F.T. Note Technique,No.7 Hughes, J.F.,1971,The Principal Timber Trees of Cameroon,Unpublished data Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London Kryn, J.M., Forbes, E.W.,1959,The Woods of Liberia,U.S.A. Department of Agriculture,Forest Products Laboratory, Madison,,Report No. 2159 Kunkel, G.,1965,The Trees of Liberia,German Forestry Mission to Liberia Report,No.3 Sallenave, P.,1955,Proprietes Phyiques et Mecaniques des Bois Tropicaux de l'Union Francaise,C.T.F.T Sallenave, P.,1964,Proprietes Physiques et Mecaniques des Bois Tropicaux (Premier Supplement,C.T.F.T. Publ.,no.23 Sallenave, P.,1971,Proprietes Physiques et Mecaniques des Bois Tropicaux (Deuxieme,Supplement,C.T.F.T. 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