Mulga

Mulga can be a small tree up to 9 m, with a well-defined main stem and angled branches, or a shrub 2 to 5 m tall with highly angled branches. The species has a very wide distribution, from Western Australia near Shark Bay, through central Australia to mid-west Queensland and New South Wales. It is rare in the Simpson and Great Victoria Deserts. Mulga grows in all states except Victoria and Tasmania. Mulga grows on flood and erosion plains and scattered on slopes and ridges. It is generally in low open woodland or tall shrubland, often in pure stands, but may be found with mallees, low shrubs and grasses.

Wood description [more info]
Heartwood is dark brown, with contrasting markings of golden yellow, and very hard. There is a narrow band of yellowish sapwood. The wood is very close-textured.

Wood density [more info]
Green density is about 1330 kg/m3, air-dry density about 1200 kg/m3, and basic density about 1025 kg/m3.

Shrinkage [more info]
Tangential and radial shrinkage are about 2.3 and 2.0 per cent respectively.

Workability [more info]
Goldfields craftsmen rate mulga as good for turning, machinability, drilling, screwholding and gluing, and excellent for sanding and finishing.

Durability [more info]
Although the durability has not been formally assessed, general use since settlement indicates that the species would be CSIRO Durability Class 1.

Strength group and properties [more info]
Green and dry strength groups are (S2) and (SD2). The brackets indicate conservative provisional ratings based on the air-dry density. The more important strength properties for those strength groups are listed in the table below.

Uses [more info]
Major use has been as fence posts in Goldfields pastoral areas and in farming areas on the south coast of WA. The species is important for fence posts. The wood turns well and takes a high polish. Traditional uses included spears, clubs and boomerangs. Settlers used it for fencing because of its very high durability, and it is still used today. Other current use is for small ornamental articles for the tourist industry. The tree is important for fodder over a wide area of Australia.

Availability [more info]
Fence posts are readily available, but sawn dried timber is difficult to obtain.