Acacia harpophylla. Family: Mimosaceae
- Medium-size tree to 24m with a spread of 4m. Diameter up to 0.6m.
- Bark is deeply furrowed longitudinally and hard.
- Bark is dark brown, dark grey to black.
- Occurs inland from the coast to the central west of eastern Australia.
- Extensively cleared in the past for agriculture. Remaining stands and vegetation associations have conservation status.
- Heartwood is commonly dark brown, but sometimes dark reddish-brown.
- Sapwood is thin, yellow and quite distinct.
- Close, relatively straight grain.
- Historically used for mining timbers.
- Historically used for small heavy construction, fence posts and rails.
- Fancy turnery.
- Walking sticks.
- Heavy axe and tool handles.
- Fishing rods.
- Formerly used for musical instruments such as fingerboards and bows.
- Used by Aboriginal peoples for spear shafts, boomerangs and nulla-nullas.
- Density: 1025kg/m3 at 12% content; about 1.0m3 of seasoned sawn timber per tonne.
- Strength groups: S1 unseasoned, SD1 seasoned.
- Stress grades: F14, F17, F22, F27 (unseasoned), F22, F27, F34 (seasoned) when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded hardwood for structural purposes.
- Joint groups: J1 unseasoned, JD1 seasoned.
- Shrinkage to 12% MC: 4.7% (tangential), 2.6% (radial).
- Unit shrinkage: 0.39% (tangential), 0.28% (radial)—these figures apply to timber reconditioned after seasoning.
- Durability above-ground: Class 1 (life expectancy more than 40 years).
- Durability in-ground: Class 1 (life expectancy more than 25 years).
- Lyctine susceptibility: untreated sapwood susceptible to lyctine borer attack.
- Termite resistance: resistant.
- Preservation: sapwood will impregnate with preservative.
- Seasoning: dries slowly with little degrade.
- Hardness: very hard (rated 1 on a 6-class scale) to indent and work with hand tools.
- Machining: firm but not difficult to work, although hard on tool edges; planes with a fine finish and takes a high polish; sanding dust can irritate your nose and eyes and may cause dermatitis.
- Fixing: no difficulties using standard fittings and fastenings.
- Gluing: satisfactorily bonds using standard procedures.
- Finishing: readily accepts paint, stain and polish.
- Sapwood: white to yellow, with distinct heartwood boundary.
- Heartwood: dark brown, chestnut brown, often variegated.
- Texture: fine, interlocked grain.
- Vessels: solitary, 2–5 radial rows, small, numerous, indistinct without lens.
Research and resources
- Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
- Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
- Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
- Queensland Government, DAF 2018, Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
- Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.
- Last reviewed: 12 Dec 2018
- Last updated: 12 Dec 2018