Grey box

Scientific name

Eucalyptus moluccana, E. woolsiana ssp. Microcarpa. Family: Myrtaceae

Local name

Gum-topped box

Description and natural occurrence

A medium-sized tree attaining a height of 20-30 m and 1 m in stem diameter. The trunk is generally straight and of good form. A finely tessellated grey coloured box-type bark is persistent to the base of the branches, where it changes to a smooth light grey bark which is often shed in ribbons.

Eucalyptus moluccana occurs throughout the central and northern coastal areas of New South Wales and Eastern Queensland, from Jervis Bay in the south to Atherton Tableland in the north.

Eucalyptus woolsiana ssp. microcarpa is common in the wheatbelt areas of Victoria, New South Wales and Queensland. It also has a limited occurrence in the Flinders and Mt Lofty Ranges of South Australia.

Wood appearance

Colour. Heartwood is usually pale brown but sometimes yellowish in colour. Sapwood usually distinct and lighter in colour.

Grain. Fine, uniform, even textured, usually interlocked.

Wood properties

Density. 1105 kg/m3 at 12% moisture content; approximately 1.0 m3 of seasoned sawn timber per tonne.

Strength groups. E. moluccana S2 unseasoned; SD2 seasoned. E. woolsiana ssp. microcarpa (S2) unseasoned; (SD2) seasoned.

Stress grades. F11, F14, F17, F22 (unseasoned), F17, F22, F27, F34 (seasoned), when visually stress graded in accordance with AS 2082-2000, Timber - hardwood - visually stress-graded for structural purposes.

Joint groups. J1 unseasoned; JD1 seasoned.

Shrinkage to 12% MC. 7.4% (tangential); 0.23% (radial).These values are for E. moluccana only.

Unit shrinkage. 0.43% (tangential); 0.23% (radial). These values apply to timber of E. moluccana reconditioned after seasoning.

Durability above-ground. Class 1 - life expectancy over 40 years.

Durability in-ground. Class 1 - life expectancy over 25 years.

Lyctine susceptibility. Sapwood is susceptible to lyctid borer attack.

Termite resistance. Resistant.

Preservation. Sapwood readily accepts preservative impregnation.

Seasoning. Can be satisfactorily dried using conventional air and kiln seasoning methods.

Hardness. Very hard (rated 1 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining. Machines and dresses well.

Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing. As with most high-density species, machining and surface preparation should be done immediately before gluing.

Finishing. Will readily accept paint, stain and polish.

Uses

Engineering. As sawn and round timber in wharf and bridge construction, railway sleepers, poles, piles, mining timbers.

Construction. As unseasoned timber in general house framing, and as seasoned dressed timber in cladding, internal and external flooring, lining and joinery. Also in fencing, landscaping and retaining walls.

Decorative. Outdoor furniture, turnery, joinery.

Others. Boat building (keel and framing components, planking), carriage building, mallet heads, mauls, sporting goods, croquet mallets, paving blocks, fuelwood.

Identification features

General characteristics

Sapwood. Pale grey-brown.

Heartwood. Light brown to yellow brown.

Texture. Uniform and fine. Grain generally interlocked.

Wood structure

Vessels. Small, numerous, mostly solitary. Heavily tylosed.

Parenchyma. Not visible with hand lens.

Rays. Very fine.

Other features

Burning splinter test. A match size splinter burns to buff ash.

Further reading

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.

Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn, McGraw-Hill, Sydney.

Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.

Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.

Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.

Last updated 04 August 2010