Scientific Name
Acacia decurrens
Trade Name
Green wattle
Family Name
Leguminosae
Synonyms
Acacia decurrens, Acacia mollissima
Common Names
Basboom, Black acacia, Black wattle, Green wattle, Swartwattel, Tan wattle, Wattle
Regions of Distribution
Africa, Central America, North America, Oceania and S.E. Asia
Countries of Distribution [VIEW MAP]
Australia, Costa Rica, India, South Africa, Sri Lanka, United States
Common Uses
Barge fenders, Boxes and crates, Building materials, Chairs, Charcoal, Chemical derivatives, Chests, Concealed parts (Furniture), Cooperages, Desks, Dining-room furniture, Docks, Dockwork, Dowell pins, Dowells, Drawer sides, Fine furniture, Floor lamps, Flooring, Flooring: industrial heavy traffic, Fuelwood, Furniture , Furniture components, Furniture squares or stock, Furniture, Harbor work, Hatracks, Interior construction, Interior trim, Kitchen cabinets, Living-room suites, Marine construction, Millwork, Mine timbers, Naval architecture, Office furniture, Poles, Posts, Pulp/Paper products, Radio – stereo – TV cabinets, Raft floats, Rafts, Rustic furniture, Stools, Tables , Tool handles, Utility furniture, Wardrobes, Wharf construction
Environmental Profile
| Seeds easily |
A horticultural variety
Distribution Overview
Originates from Australia (Qld. and NSW, though naturalized in Vic., Tas. and ACT), but has been introduced into other areas of the world.
Heartwood Color
| Brown | ||||||||||||
| Red | ||||||||||||
| Yellow | ||||||||||||
| Black | ||||||||||||
| Highly variable | ||||||||||||
| Pink | ||||||||||||
| Orange | ||||||||||||
| Pale brown | ||||||||||||
| Red | ||||||||||||
| Yellow to golden-yellow to orange | ||||||||||||
| Pale red to pink | ||||||||||||
| Gold | ||||||||||||
| Dark brown | ||||||||||||
| Color varies considerably | ||||||||||||
| Bark inclusions are common |
To facilitate matching, it is suggested that sawn lumber from each log be stored separately
Sapwood Color
| White | ||||||||||||
| Different than heartwood | ||||||||||||
| Cream |
Grain
| Figure | ||||||||||||
| Interlocked | ||||||||||||
| Other (figure) |
| Other figure | ||||||||||||
| Interlocked |
Texture
| Fine | ||||||||||||
| Medium | ||||||||||||
| Fine | ||||||||||||
| Fine to medium |
Luster
| Medium | ||||||||||||
| High | ||||||||||||
| Lustrous | ||||||||||||
| High |
Natural Durability
| Susceptible to insect attack | ||||||||||||
| Non-resistant to powder post beetles | ||||||||||||
| Non-durable | ||||||||||||
| Very durable | ||||||||||||
| Non-resistant to termites | ||||||||||||
| Perishable | ||||||||||||
| Susceptible to attack from powder post (Lyctid & Bostrychid) beetles | ||||||||||||
| Non durable | ||||||||||||
| Susceptible to attack from termites (Isoptera) | ||||||||||||
| Very high natural resistance |
Odor
| No specific smell or taste |
Kiln Schedules
| Drying (speed) is fast | ||||||||||||
| Dry at a slow speed |
Drying Defects
| Distortion | ||||||||||||
| Splitting | ||||||||||||
| Checking | ||||||||||||
| Moderate end spitting | ||||||||||||
| Severe cupping | ||||||||||||
| Moderate surface checking | ||||||||||||
| Slight twist/warp | ||||||||||||
| Severe twisting/warping | ||||||||||||
| Moderate cupping |
Ease of Drying
| Fairly Easy | ||||||||||||
| Thick Stock Requires Care | ||||||||||||
| Rapidly | ||||||||||||
| Slowly | ||||||||||||
| Moderately Difficult to Difficult | ||||||||||||
| Requires slow to moderate drying schedule. | ||||||||||||
| Moderate |
Kiln Drying Rate
| Naturally dries slowly | ||||||||||||
| Naturally dries quickly |
Tree Size
| Tree height is 10-20 m | ||||||||||||
| Tree height is 0-10 m | ||||||||||||
| Tree height is 20-30 m |
Boring
| Fairly easy to very easy | ||||||||||||
| Fair to good results | ||||||||||||
| Fair results |
Cutting Resistance
| Easy to saw | ||||||||||||
| Cutting Resistance with dry wood is easy | ||||||||||||
| Easy to saw |
Mortising
| Fairly Easy to Very Easy | ||||||||||||
| Fair to Good Results | ||||||||||||
| Mortising characteristics fair or medium |
Movement in Service
| Unstable with Poor Stability – Large Movement | ||||||||||||
| Large |
Nailing
| Pre-Boring Recommended | ||||||||||||
| Possible if prebored |
Planing
| Fairly Difficult to Very Difficult | ||||||||||||
| Fairly Easy to Very Easy | ||||||||||||
| Difficult to plane | ||||||||||||
| May produce some torn grain |
Resistance to Impregnation
| Permeable sapwood | ||||||||||||
| Resistant heartwood | ||||||||||||
| Resistant sapwood | ||||||||||||
| Permeable heartwood | ||||||||||||
| Sapwood is permeable | ||||||||||||
| Heartwood is moderately resistant | ||||||||||||
| Permeable | ||||||||||||
| Difficult to treat with preservatives |
Response to Hand Tools
| Fairly Difficult to Difficult to Work | ||||||||||||
| Difficult to machine |
Screwing
| Fairly Easy to Very Easy | ||||||||||||
| Fair to Good Results | ||||||||||||
| Satisfactory screwing characteristics |
Strength Properties
| Density (dry weight) = 46-52 lbs/cu. ft. | ||||||||||||
| Max. crushing strength = high | ||||||||||||
| Hardness (side grain) = medium | ||||||||||||
| Shearing strength (parallel to grain) = medium | ||||||||||||
| Bending strength (MOR) = medium | ||||||||||||
| Modulus of Elasticity (stiffness) = medium | ||||||||||||
| Bending strength (MOR) = high | ||||||||||||
| Modulus of Elasticity (stiffness) = high | ||||||||||||
| Toughness-Hammer drop (Impact strength)= high | ||||||||||||
| Toughness (total work)= very high | ||||||||||||
| Modulus of Elasticity (stiffness) = low | ||||||||||||
| Max. crushing strength = medium | ||||||||||||
| Density (dry weight) = 38-45 lbs/cu. ft. |
Numerical Data
| Item | Green | Dry | English |
| Bending Strength | 11249 | 17470 | psi |
| Density | 46 | lbs/ft3 | |
| Hardness | 1658 | lbs | |
| Impact Strength | 54 | inches | |
| Maximum Crushing Strength | 6568 | 9550 | psi |
| Shearing Strength | 2205 | psi | |
| Stiffness | 1798 | 2074 | 1000 psi |
| Toughness | 470 | inch-lbs | |
| Weight | 45 | 37 | lbs/ft3 |
| Item | Green | Dry | Metric |
| Bending Strength | 790 | 1228 | kg/cm2 |
| Density | 737 | kg/m3 | |
| Hardness | 752 | kg | |
| Impact Strength | 137 | cm | |
| Maximum Crushing Strength | 461 | 671 | kg/cm2 |
| Shearing Strength | 155 | kg/cm2 | |
| Stiffness | 126 | 145 | 1000 kg/cm2 |
| Toughness | 541 | cm-kg |
References
Banks, C.H., Schoeman, J.P., Otto, K.P.,1977,The Mechanical Properties of Timbers with particular reference to South,Africa,South African Forestry Research Institute Bulletin,(Ed.,Schoeman, J.P. 1973 & Otto K.P. 1976,No.48
Banks, C.H.,1954,The Mechanical Properties of Timbers with Particular Reference to those,grown in the Union of South Africa,Journal of the South African Forestry Association,No. 24 pp.44-65,[South,African Forestry Journal]
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
Bolza, E., Kloot, N.H.,1963,The Mechanical Properties of 174 Australian Timbers,C.S.I.R.O. Division of Forest Products Technological Paper,No.25
Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison.
Dave Faison. Into the Woods. Personal Communication, 1993.
E.H. Walker,1954,Important Trees of the Ryukyu Islands,United States Civil Administration of the Ryukyu Islands Special Bulletin,No. 3
Farmer, R.H.,1972,Handbook of Hardwoods,HMSO
Guha, S.R.D.,1969,Summary of Investigations on the suitability of Indigenous Broadleaved,woods for production of Sulphate pulps for writing and printing,Indian Forester,95(8,pp579-90
Hartwig, G.L.F.,1967,Flooring Timber in S.Africa – Acacia mearnsii,The South African Builder 45(2) pp34-35
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)
Little, E.L.,1948,A Collection of Tree Specimens from Western Ecuador,Caribbean Forester,9(3,pp215-98
Nation Research Council,1980,Firewood Crops Shrub and Tree Species for Energy Production,National Academy of Sciences, Washington D.C.
Rao, K.R. and S.K. Purkayastha. 1972. Indian Woods – Their Identification, Properties and Uses, Volume III – Leguminosae to Combretaceae. Published by the Manager of Publications, Delhi, India.
Scott, M.H.,1935,Weights of South African Growth Timbers,South African Department of Agriculture and Forestry Bulletin,No.145,Forest Products Institute, Forestry Series No.1
Scott, M.H.,1953,Utilisation Notes on South African Timbers,South African Forestry Department Bulletin No.36
South African Lumber Millers Assoc.,1969,Notes on some Commercially Available Hardwoods,S.A.L.M.A. Timber Info. Centre Timber Technical Guide,No.1
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]