Grey gum

Scientific name

Eucalyptus propinqua var. propinqua, E. punctata. Family: Myrtaceae

Other names

Grey iron gum (both species); small fruited grey gum E. propinqua var. propinqua


  • Grows to 40m high and 1m diameter.
  • Form is generally good on better sites with a straight bole (trunk) extending for half or two-thirds the tree's height.
  • Bark decorticates (sheds) in large irregular patches exposing a cream to bright-orange surface, which weathers to grey or grey-brown.


  • Varieties of grey gum occur along the east coast of Australia from Wyong, New South Wales, to Maryborough and inland to the Carnarvon Ranges and Blackdown Tablelands in Queensland.



  • Heartwood is red to red-brown.
  • Sapwood is distinctly paler.


  • Grain usually interlocked, with coarse but even texture.
  • Occasionally marked by grub holes.


  • Engineering: railway sleepers, landscaping sleepers, cross-arms, poles, piles, mining timbers.
  • Construction: framing, flooring, retaining walls.
  • Others: boat building, butcher's blocks.


  • Density: 1055kg/m3 at 12% moisture content; about 1.0m3 of seasoned sawn timber per tonne.
  • Strength groups: S1 unseasoned, (SD2) seasoned.
  • Stress grades: F14, F17, F22, F27 (unseasoned); F17, 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: 7.0% (tangential), 4.5% (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 not susceptible to lyctid borer attack.
  • Termite resistance: resistant.
  • Preservation: sapwood readily accepts preservative.
  • Seasoning: slow to dry, but little degrade occurs.
  • Hardness: very hard (rated 1 on a 6-class scale) to indent and work with hand tools.
  • Machining: machines well, however, be careful with interlocked grain.
  • Fixing: no difficulties with 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.

Identification features

General characteristics

  • Sapwood: pale, reddish brown distinguishable from heartwood.
  • Heartwood: reddish brown to red.
  • Texture: medium to coarse, interlocked grain.

Wood structure

  • Vessels: small, solitary, uniform distribution; vessel lines prominent in some specimens of darker colour; abundant tyloses.
  • Parenchyma (soft tissue): not visible with lens.
  • Rays: fine.

Other features

  • Burning splinter test: match-size splinter burns to charcoal leaving no ash.

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.