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Blunting Effect Boring Comments Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Luster Moulding Movement in Service Nailing Natural Durability Natural Growth Defects Numerical Data Odor Planing Polishing Product Sources References Regions of Distribution Resistance to Impregnation Response to Hand Tools Sapwood Color Scientific Name Screwing Staining Steam Bending Texture Trade Name Tree Size Veneering Qualities		Scientific Name Tarrietia utilis Trade Name Niangon Family Name Common Names De-orh, Niangon, Nyankom, Wishmore, Yawe Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Cameroon, Gambia, Ghana, Guinea Bissau, Guinea, Ivory Coast, Liberia, Senegal, Sierra Leone Common Uses Boat building, Decorative veneer, Flooring, Furniture , Furniture components, General carpentry, Greenhouses, Joinery, Plywood, Veneer Environmental Profile Vulnerable in parts of its natural habitat Status unknown in some areas due to inadequate information May soon become Endangered if over-exploitation and habitat destruction persists Generally secure within most of its natural habitat, but note exceptions. Data source is World Conservation Monitoring Center Vulnerable in Liberia. Its status in the wild in Gabon, Ghana, and Sierra Leone is listed as unknown because of inadequate information Distribution Overview The natural habitat of West Africa, extending from Sierra Leone to Ghana. It occurs in the lowlands as well as in hilly areas. Heartwood Color Brown Yellow Orange Green/grey White Red Pale reddish brown Pale red to pink Darkens with age Sapwood Color White Yellow Brown Red Whitish Not always distinct from the heartwood Sapwood is up to 3 inches (7.5 cm) wide Grain Closed Sometimes wavy Commonly interlocked High rays are reported to produce a distinct attractive figure on radial surfaces Texture Medium Coarse Fine Moderately coarse Resin content gives the wood a greasy feel Luster Medium Medium Dull Natural Growth Defects High levels of gum which exude on the surface Brittleheart is often frequent and extensive Gum Exudation Some logs may contain brittleheart, with diameters reaching 8 inches (20 cm). The wood contains high levels of gum which tends to exude on the surface and interfere with some finishing operations Natural Durability Susceptible to insect attack Moderately durable Non-resistant to powder post beetles Non-durable Resistant to powder post beetles Perishable Non-resistant to termites Sapwood is readily attacked by powder-post beetles Naturally resistant to decay fungi and other wood destroying insects Odor No specific taste May have a slightly disagreeable smell when green Kiln Schedules T6-D2 (4/4); T3-D1 (8/4) US Schedule E (4/4) United Kingdom/T6-D2 (4/4); T3-D1 (8/4) US Schedule E (4/4) United Kingdom Drying Defects Splitting Checking Slight tendency to end-split, surface check and collapse Slight distortion may occur during drying May check slightly and some 1 inch (25 mm) thick boards may twist during drying Ease of Drying Fairly Easy Rapidly Slight tendency to degrade Air dries fairly rapidly Radial = 2.5% Shrinkage Green to 12% MC Tangential = 4.5% Kiln Drying Rate Naturally dries quickly Tree Size Tree height is 30-40 m The tree is reported to often develop stilted roots in swampy areas. It is usually buttressed Product Sources The timber is often marketed under the trade name Niangon with another similar but darker and somewhat heavier wood produced by (T. densiflora), which grows mainly in Central Africa. The International Tropical Timbers Organization reports that Niangon is a fairly important source of timber in the producing countries, although production is decreasing. Niangon is a regular export commodity. Comments Generally strong, tough, and hard. It has medium strength in bending and crushing, and low strength in stiffness and resistance to shock loads. The timber has been recommended for use in exposed conditions such as external doors, frames, and greenhouses Blunting Effect Little Moderate Medium dulling effect on cutting edges Boring Responds satisfactorily to boring, turning and other wood working operations Severely interlocked grain tends to affect results Cutting Resistance Easy to saw Material with interlocked grain can be difficult. Sawing and other machining properties are affected by interlocked grain, which can be rather severe. A long tooth pitch is essential in rip-sawing to prevent sawdust from packing and causing overheating of saw blades. Break-out at bottom of cut is very common in cross-cutting Gluing Fairly Easy to Very Easy May require surface treatment for best results Good gluing properties Pre-Treatment of the surface with a caustic soda solution or ammonia is recommended to remove exuded gum Moulding Clean surfaces are somewhat difficult to achieve A french head is most suitable for moulding operations Movement in Service Moderate dimensional stability after seasoning Medium Nailing Fairly Easy to Very Easy Very Good to Excellent Results Fair to Good Results Tends to split during nailing Holds nails well Planing Very Good to Excellent Results Fair to Good Results The timber works rather easily in general, but quarter sawn material requires a reduced planing angle of 15 degrees to prevent grain from tearing Resistance to Impregnation Resistant heartwood Resistant sapwood Poor response to preservative treatment The heartwood responds very poorly to preservative treatment, and the sapwood is difficult to treat. Response to Hand Tools Easy to Work Moderate dulling of cutting edges Easy to machine Screwing Fair to Good Results Veneering Qualities Suitable for slicing Veneers easily Veneers moderately easy Difficult to veneer Suitable for peeling Suitable for slicing into decorative veneers Niangon is converted by rotary cutting for the manufacture of plywood. Figured logs are sliced into decorative veneers for decorative applications. Steam Bending Variable steam bending qualities Moderate Knots are reported to have little impact on bending properties Polishing Fair to Good Results Very Good to Excellent Results Requires a filler Good results Requires considerable filler Staining Fair to Good Results Surface preservation treatments are rather difficult, and usually require to be preceded by preparation with ammonia or caustic soda Numerical Data Item Green Dry English Bending Strength 9496 12103 psi Density 38 lbs/ft3 Hardness 1078 lbs Impact Strength 27 31 inches Maximum Crushing Strength 4986 7056 psi Shearing Strength 1587 psi Stiffness 1279 1447 1000 psi Work to Maximum Load 10 10 inch-lbs/in3 Specific Gravity 0.53 0.54 Weight 48 37 lbs/ft3 Item Green Dry Metric Bending Strength 667 850 kg/cm2 Density 608 kg/m3 Hardness 488 kg Impact Strength 68 78 cm Maximum Crushing Strength 350 496 kg/cm2 Shearing Strength 111 kg/cm2 Stiffness 89 101 1000 kg/cm2 Work to Maximum Load 0.70 0.70 cm-kg/cm3 Specific Gravity 0.53 0.54 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 Boone, R.S., C.J. Kozlik, P.J. Bois and E.M. Wengert. 1988. Dry Kiln Schedules for Commercial Woods: Temperate and Tropical. United States Department of Agriculture, Forest Service, General Technical Report FPL-GTR-57, Forest Products Laboratory, Madison, Wisconsin. Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. 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. ITTO. 1986. Tropical Timber Atlas, Volume 1 - Africa. Prepared for International Tropical Timber Organization (ITTO) by Centre Technique Forestier Tropical (CTFT, Division of CIRAD, 45bis, Avenue de la Belle Gabrielle, Nogent-sur-Marne Cedex, France. Lavers, G.M. 1967. The Strength Properties of Timbers. Forest Products Research Bulletin, No. 50 (Spersedes Bulletin No. 45). Ministry of Technology, Her Majesty's Stationery Office, London. Lincoln, W.A. 1986. World Woods in Color. Linden Publishing Co. Inc. Fresno, California. WCMC. 1992. Conservation Status Listing: Trees and Timbers of the World. World Conservation Monitoring Center (WCMC, Plants Program, 219 Huntingdon Road, Cambridge, CB3 ODL, United Kingdom.