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Clicking any heading in the main data area (at right) will scroll the page back to this top position. Use the following links to jump to the associated section in the main data. Blunting Effect Common Names Common Uses Countries of Distribution Cutting Resistance Drying Defects Ease of Drying Family Name Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Luster Moulding Movement in Service Nailing Natural Durability Numerical Data Painting Planing Polishing References Regions of Distribution Resistance to Impregnation Response to Hand Tools Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Synonyms Texture Toxicity Trade Name Tree Identification Tree Size Turning Veneering Qualities Scientific Name Mitragyna rubrostipulacea Trade Name Abura Family Name Rubiaceae Synonyms Mitragyna rubrostipulata, Mitragyne rubrostipulacea, Mitragyne rubrostipulata, Adina rubrostipulata, Hallea rubrostipulata Common Names Abura, Mromberomba, Mromberombbe, Muho, Munyzmaizi, Mutoro, Mutororo, Muzingu, Nazingu, Ngomera, Nzin, Nzingu, Obul, Omuzito, Oo, Romberombe Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Tanzania, Uganda Common Uses Boxes and crates, Cabinetmaking, Carvings, Flooring, Furniture, Joinery, Light construction, Moldings, Plywood corestock, Plywood, Pulp/Paper products, Toys, Vats, Veneer, Veneer: decorative Heartwood Color Yellow Brown Orange Red Pale red to pink Pale brown Brown White to cream Sapwood Color White Yellow Grain Straight Figure Weak (figure) Even Growth rings (figure) Straight Weak figure Clear growth rings (figure) Texture Fine Medium Fine Fine to medium Luster Dull Natural Durability Durable Perishable Non-durable Susceptible to insect attack Non-resistant to powder post beetles Non-resistant to termites Non-resistant to marine borers Perishable Susceptible to attack from termites (Isoptera) Non durable Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Pinworms (ambrosia beetles) are commonly present Moderately durable Toxicity Some toxic effects Kiln Schedules Dry at a slow speed Kiln Drying Rate (in days) is fairly rapid Drying (speed) is fast UK=K US=T13C4S/T11D3S UK=H US=T10D4S/T8D3S Fr=7 UK=C US=T3C2/T3C1 Fr=3 Drying Defects Splitting Moderate end spitting Slight end splitting Moderate cupping Slight twist/warp No twisting or warping No surface checking Slight surface checking Slight cupping Ease of Drying Fairly Easy Rapidly Easy Kiln Drying Rate Naturally dries quickly 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 not buttressed Tree Size Tree height is 20-30 m Bole length is 10-20 m Bole length is 0-10 m Blunting Effect Blunting effect on machining is slight Cutting Resistance Easy to saw Cutting Resistance with green wood is easy Cutting Resistance with dry wood is easy Gluing Fairly Easy to Very Easy Easy to glue Moulding Good finishing results Movement in Service Excellent Stability - Small Movement Medium Small Nailing Fairly Easy to Very Easy Easy to nail Holds satisfactorily Planing Good planing finish Resistance to Impregnation Resistant heartwood Resistant sapwood Heartwood is permeable Sapwood is permeable Heartwood is moderately resistant Response to Hand Tools Easy to Work Easy to machine Screwing Fairly Easy to Very Easy Turning Difficult to turn Veneering Qualities Veneers easily Veneers moderately easy Suitable for peeling Easy to cut Steam Bending Fair to Good Results Very Good to Excellent Results Painting Good results Polishing Very Good to Excellent Results Fair to Good Results Satisfactory results Good results Staining Finish is generally satisfactory Finish is generally good Strength Properties Density (dry weight) = 31-37 lbs/cu. ft. Shrinkage, Radial = small Shrinkage, Radial = fairly large Max. crushing strength = medium Bending strength (MOR) = low Toughness-Hammer drop (Impact Strength) = low Shrinkage, Radial = moderate Shearing strength (parallel to grain) = very low Modulus of Elasticity (stiffness) = low Hardness (side grain) = soft Shrinkage, Radial = very small Shrinkage, Radial = large Density (dry weight) = 38-45 lbs/cu. ft. Density (dry weight) = 23-30 lbs/cu. ft. Shrinkage, Tangential = moderate Numerical Data Item Green Dry English Bending Strength 6111 9589 psi Density 33 lbs/ft3 Hardness 995 lbs Impact Strength 28 inches Maximum Crushing Strength 3916 6397 psi Shearing Strength 882 psi Stiffness 1358 1568 1000 psi Weight 32 25 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 7 % Item Green Dry Metric Bending Strength 429 674 kg/cm2 Density 528 kg/m3 Hardness 451 kg Impact Strength 71 cm Maximum Crushing Strength 275 449 kg/cm2 Shearing Strength 62 kg/cm2 Stiffness 95 110 1000 kg/cm2 Weight 512 400 kg/m3 Radial Shrinkage 4 % References Bois, P.J.,1966,The Strength Properties of Tanzania Timbers,Tanzania Forest Div. Util. Sec. Moshi Tech. Note, No.35 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 Bryce, J.M.,1967,Commercial Timbers of Tanzania,Tanzanian Forestry Division Util. Sec. Moshi Eggeling, W.J.,1940,Indigenous Trees of Uganda,Govt. Printer Entebbe Uganda 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 Grant, D.K.S.,1934,Some Local Timbers,Tanzania Forest Department Murira, K.,1984,Natural Durability Tests of Tanzanian Timbers 1955 - 1982,Tanzania Forestry Research Institute, Timber Utilisation Research Centre,,Moshi. 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 Tanzania Forest Division,1966,Kiln Drying Schedules for Tanzania Timbers Technical Note no.38,Tanzania Forest Div. Util. Sec. Moshi Tanzania Forest Division,1966,Mitragyna rubrostipulata (nzingu/mromberombe,Tanzania Forest Div. Util. Sec. Moshi - Timbers of Tanganyika Uganda Forest Department,1954,Abura (Mitragyna stipulosa and Mitragyna rubrostipulata,Uganda Forest Div. Util. Sec. Timber Leaflet,No.6