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Blunting Effect Boring Carving Certified Source Common Names Common Uses Countries of Distribution Cutting Resistance Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Luster Mortising Moulding Movement in Service Nailing Natural Durability Numerical Data Odor Painting Planing Polishing References Regions of Distribution Resistance to Impregnation Resistance to Splitting Response to Hand Tools Routing & Recessing Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Synonyms Texture Toxicity Trade Name Tree Identification Tree Size Turning Veneering Qualities		Scientific Name Celtis zenkeri Trade Name African celtis Family Name Ulmaceae Synonyms Celtis stuhlmannii Common Names African celtis, Asan, Atako, Ba, Bolonde, Bunyoro, Celtis, Esa, Esa-kokoo, Gombi, Ita, Ita-gidi, Itako, Kayombo, Killiakamba, Kisisa, Luniumbu, Mengo, Mukokukoma, Mukomukoma, Namanuka, Odou, Odu, Odu elias, Ohia, Shiunza, Toro, Yisa, Yisa-kokoo, Yisapie Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Angola, Congo, Ghana, Guinea, Sudan, Tanzania, Uganda Common Uses Agricultural implements, Flooring, Fuelwood, Furniture, Heavy construction, Joinery, Light construction, Millwork, Plywood, Posts, Sporting Goods, Textile equipment, Tool handles, Turnery, Vehicle parts Environmental Profile Rare Abundant/Secure Questionable Heartwood Color Brown Yellow Orange White Red Pink Tan White to cream Yellow to golden-yellow to orange Greenish to greyish Pale brown Sapwood Color White Yellow Brown Red Same as heartwood Grain Figure Straight Other (figure) Interlocked Even Straight Other figure Interlocked Texture Fine Coarse Medium Fine Coarse Fine to medium Luster Medium Pronounced Lustrous Natural Durability Durable Very durable Susceptible to insect attack Resistant to powder post beetles The sapwood is susceptible to wood staining fungal attack Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Perishable Susceptible to attack from termites (Isoptera) Non durable Pinworms (ambrosia beetles) often present in the standing tree Pinworms (ambrosia beetles) may be present in the felled log Pinworms (ambrosia beetles) are commonly present Moderately durable Odor Has a taste Has an odor Toxicity Some toxic effects Kiln Schedules Drying (speed) is fast Kiln Drying Rate (in days) is fairly rapid Dry at a slow speed Drying Defects Distortion Slight end splitting Slight cupping Ease of Drying Fairly Easy Rapidly Slowly Reconditioning Treatement Moderately Difficult to Difficult Kiln Drying Rate Naturally dries at a moderate speed Fairly rapid (11-17 days for boards under 32 mm, to 31-51 days for boards greater than 63 mm) Tree Identification Bole/stem form is buttressed Bole/stem form is straight Bole/stem form is misshapen Tree Size Tree height is 60-70 m Tree height is 50-60 m Bark width is greather than 50 mm Tree height is 40-50 m Trunk diameter is 100-150 cm Tree height is 20-30 m Bole length is 40-50 m Tree height is greater than 70 m Tree height is 30-40 m Trunk diameter is 150-200 cm Trunk diameter is 200-250 cm Certified Source Certified Source Blunting Effect Little Blunting effect on machining is moderate Boring Very good to excellent results Fairly easy to very easy Carving Fair to Good Results Fairly Easy to Very Easy Cutting Resistance Cutting Resistance with dry wood is easy Cutting Resistance with dry wood is difficult Gluing Very Good to Excellent Results Fairly Easy to Very Easy Easy to glue Mortising Fairly Easy to Very Easy Very Good to Excellent Results Fairly Difficult to Very Difficult Fair to Good Results Moulding Fairly Easy to Very Easy Very Good to Excellent Results Fairly Difficult to Very Difficult Movement in Service Excellent Stability - Small Movement Medium Small Nailing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Poor to Very Poor Results Difficult to nail Pre-boring recommended Planing Fairly Easy to Very Easy Fair to Good Results Fairly Difficult to Very Difficult Resistance to Impregnation Resistant heartwood Permeable sapwood Resistant sapwood Heartwood is moderately resistant Sapwood is permeable Resistance to Splitting Excellent Response to Hand Tools Easy to Work Fairly Difficult to Difficult to Work Easy to machine Moderate difficulty Difficult to machine Routing & Recessing Fair to Good Results Fairly Easy to Very Easy Screwing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Turning Very Good to Excellent Results Fairly Easy to Very Easy Good results Easy to turn Veneering Qualities Veneers moderately easy Veneers easily No drying degrade Suitable for peeling Steam Bending Unsuitable Poor to Very Poor Results Moderate Painting Fair to Good Results Very Good to Excellent Results Polishing Fair to Good Results Very Good to Excellent Results Fairly Easy to Very Easy Satisfactory results Staining Fair to Good Results Very Good to Excellent Results Fairly Easy to Very Easy Finish is generally satisfactory Strength Properties Shrinkage, Volumetric = large Shrinkage, Tangential = large Shrinkage, Tangential = fairly large Shrinkage, Radial = fairly large Bending strength (MOR) = high Shrinkage, Radial = very small Shrinkage, Radial = moderate Shrinkage, Radial = large Density (dry weight) = 46-52 lbs/cu. ft. Crushing strength = high Shrinkage, Tangential = very small Shrinkage, Tangential = small Shrinkage, Tangential = moderate Modulus of Elasticity (stiffness) = mediun Modulus of Elasticity (stiffness) = high Hardness (side grain) = medium Density (dry weight) = 38-45 lbs/cu. ft. Crushing strength = medium Numerical Data Item Green Dry English Bending Strength 13576 20956 psi Density 45 lbs/ft3 Hardness 1658 lbs Maximum Crushing Strength 5905 8762 psi Stiffness 1916 2208 1000 psi Weight 44 35 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 8 % Volumetric Shrinkage 14 % Item Green Dry Metric Bending Strength 954 1473 kg/cm2 Density 721 kg/m3 Hardness 752 kg Maximum Crushing Strength 415 616 kg/cm2 Stiffness 134 155 1000 kg/cm2 Weight 705 560 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 Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. Eggeling, W.J.,1940,Indigenous Trees of Uganda,Govt. Printer Entebbe Uganda Farmer, R.H.,1972,Handbook of Hardwoods,HMSO Forests Products Research Laboratory, U.K.,1956,A Handbook of Hardwoods,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment 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 Ivory Coast Timbers. New Series (Leaflets,C.T.F.T. Hughes, J.F.,1971,The Principal Timber Trees of Cameroon,Unpublished data Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London Keay, R.W.J.,1964,Nigerian Trees Vol.2,Nigeria Federal Department of Forest Research, Ibadan Kennedy, J.D.,1936,Forest Flora of Southern Nigeria,Government Printer Lagos Savill, P.S., Fox, J.E.D.,1967,Trees of Sierra Leone Spalt, H.A., Stern, W.L.,1956,Survey of Africa Woods 2,Tropical Woods 16(106) pp65-97 Spalt, H.A., Stern, W.L.,1956,Survey of African woods 1,Tropical Woods,115(105,pp 13-38 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 Taylor, C.J.,1960,Synecology and Silviculture in Ghana,University College of Ghana Thomas Nelson and Sons Uganda Forest Department,1954,Mukomukoma (Celtis zenkeri,Uganda Forest Department Timber Leaflet,No.31 Uganda Forest Department,1969,The Shrinkage of Some Ugandan Timbers,Uganda Forestry Department Timber Leaflet,No.47