Ironbark is the hardest timber of all the Australian species. The most common commercial species is Eucalyptus Paniculata – another species is E. siderophloia. The heartwood of the Grey Ironbarks ranges from light grey or light chocolate with some darker reds and browns sometimes occurring. Sapwood is slightly lighter in colour. Grey Ironbark may have various regional variations such as the ‘Black Ironbarks’ around Port Macquarie, which have similar light colours with black narrow to broad streaks running through the timber. Texture is moderately coarse and even.
The most common Red Ironbarks are Mugga Ironbark (Eucalyptus sideroxylon), narrow-leaved Red Ironbark (E. creba) & broad-leaved Red Ironbark (E. fibrosa). Mugga Ironbark extends from VIC through NSW into southern QLD. Narrow-leaved Red Ironbark is found in the coastal, tablelands and western plains of central to northern NSW and just west of the Great Dividing Range. Broad-leaved Red Ironbark has a distribution from the south coast of NSW to central coastal QLD. The heartwood colour is deep red. Sapwood is a very distinctive pale yellow in colour. Texture is medium and even.