Ironbark

Overview

Ironbark is a group name for several very dense eucalypts with deeply furrowed, dark bark. Grey ironbark (E. paniculata) is among the hardest and densest of Australian timbers: very hard, dense and difficult to work. It is mostly used for flooring, decking, structural and outdoor work rather than fine furniture.

Pros

• Extremely hard and dense: grey ironbark is 16 kN seasoned hardness (about 3600 lbf at 224.8 lbf per kN) and 1106 kg/m3 (WoodSolutions).
• Resistant to lyctid borers and termites (grey ironbark, WoodSolutions).
• Well suited to outdoor and heavy-wear uses.

Cons

• Very difficult to work: it dulls tools and needs pilot holes and carbide.
• Red ironbark is slow to dry and prone to surface checking (WoodSolutions).
• Heavy and tiring to handle; check load limits on joinery.
• No Wood Database entry, so there is no independent Janka lbf: all hardness here is WoodSolutions' kN figures converted.

Variants and subspecies

• Grey ironbark (E. paniculata): 16 kN, 1106 kg/m3.
• Red ironbark (E. sideroxylon): 11.9 kN, 1050 kg/m3, Least Concern; the Wikipedia article uses IUCN 2019.
• Broad-leaved ironbark: also sold under the name; I did not open data on its hardness or status. Hardness above is a seasoned-wood value in kN; the lbf in the frontmatter is for grey ironbark.

Working and finishing

Machine with sharp carbide at slow feeds, pre-drill every fastener, and expect heavy tool wear. Test glue and finish on offcuts.

Staining and finishing colour

Its density limits absorption, so stain stays shallow. Use oil, hardwax or clear coat to show the natural colour; red ironbark is already deep red-brown.

Sustainability and handling

IUCN: red ironbark is Least Concern (2019, via Wikipedia); I found no status for grey ironbark. Not found as CITES-listed in any source I read; checked 2026-09 but CITES/Species+ could not be queried directly, so verify before shipping. Ironbark is a native-forest timber, so ask for origin and any certification. I found no species-specific health reports in the sources checked; take normal hardwood-dust precautions.

Popular projects

Flooring, decking, outdoor tables and benches, posts, tool handles and heavy structural pieces.

Buying notes

I found no US retail listing. In Australia, flooring "from" prices were AUD 55 per square metre for both grey and red ironbark (roughly US$3.60 per sq ft). Ask whether you are getting grey or red, because hardness differs by roughly a quarter. See Spotted gum or Blackbutt for easier-to-work alternatives.