Ironbark; narrow-leaved ironbark; red ironbark

• Large hardwood tree.
• Bark is deeply furrowed, and grey or black.
• Grows to 30m high and 0.7m diameter.
• Grows on a wide variety of soils and is drought and frost resistant.

• Most widely distributed of the ironbarks.
• Occurs across the Great Dividing Range and inland.
• Extends from Sydney to Cairns.

Colour

• Heartwood is red-brown to dark red.
• Sapwood white to pink-white.

Grain

• Close-grained, occasionally interlocked.

• Engineering: sleepers, girders, bridgework, wharves, heavy engineering construction, poles.
• Construction: unseasoned timber in general house framing, and seasoned dressed timber in cladding, internal and external flooring, linings and joinery; also in fencing, landscaping and retaining walls.
• Decorative: despite their hardness, the ironbarks are a favourite of woodcraftsmen who have salvaged timber (e.g. old yards, fence posts) for furniture and turnery.
• Others: outdoor furniture.

• Density: 1090kg/m³ at 12% moisture content; about 0.9m³ of seasoned sawn timber per tonne.
• Strength groups: S2 unseasoned, SD3 seasoned.
• Stress grades: F11, F14, F17, F22, (unseasoned); F14, F17, F22, F27, (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: about 5% (tangential), 3.5% (radial).
• Unit shrinkage: not available.
• Durability above-ground: Class 1 (life expectancy more than 40 years).
• Durability in-ground: Class 1 (life expectancy more than 25 years).
• Lyctine susceptibility: sapwood is not susceptible to lyctid borer attack.
• Termite resistance: resistant.
• Preservation: sapwood will readily impregnate with preservatives..
• Seasoning: slow to dry, resists surface checking more than other commercial ironbarks.
• Hardness: very hard (rated 1 on a 6-class scale) to indent and work with hand tools.
• Machining: hard to work due to density and interlocking grain.
• Fixing: no difficulties using standard fittings and fastenings.
• Gluing: as with most high-density species, machine and prepare surface immediately before gluing.
• Finishing: readily accepts paint, stain and polish.

General characteristics

• Sapwood: white to pink-white, distinct from heartwood.
• Heartwood: red-brown to dark red.
• Texture: fine texture, grain is shallowly interlocked.

Wood structure

• Vessels: small, solitary and numerous; vessel lines are not obvious; vessels are tylosed.

• 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.