Around 20 species in the eucalyptus genus are commercially important as lumber. They may be sold under their own species names or simply as "eucalyptus." While these trees all have wood with similar density and a number of other common characteristics, their working properties vary significantly. Eucalyptus lumber may turn well or tend to splinter or dull tools, depending on the origins of the lumber.
Many eucalyptus species are very hard and dense, causing them to blunt tools. They may also contain some silica, which further dulls cutting edges. Use hardened wood turning tools, especially ones with carbide cutting surfaces, to reduce the rate of tool blunting. The hardness and density that causes many eucalyptus species to damage tools also produces a durable finished piece that will last for many years.
Grain type also affects eucalyptus lumber's turnability. Species such as Eucalyptus marginata, or jarrah wood, have wavy or interlocked grain patterns. These produce an appealing look in finished turned pieces, but also make the material more difficult to work. The interlocked grain may tear out easily or contribute to tool blunting. Straight-grained species and hybrids such as Lyptus produce lumber that's easier to turn, but less striking in the finished piece.
Some eucalyptus species and hybrids burn easily from friction. For instance, the heat caused by turning Lyptus wood on an electric lathe can result in undesirable marks on the surface of the wood. To reduce the risk of this problem, turn at a relatively slow speed or stop the lathe periodically to allow the wood to cool before resuming work.
Members of the Eucalyptus genus often contain gum pockets. Some contain so much gum that their common names, such as bluegum, reflect this trait. Gum pockets can interrupt the turning process, make tools sticky and mar the surface of the wood. Choose eucalyptus lumber with as few gum pockets as possible. Work carefully with wood that may include these deposits.
Since eucalyptus lumber's turning characteristics can vary so much from one species to the next, choose only lumber labelled specifically by species or variety. Generic "eucalyptus" wood could vary from highly workable Eucalyptus deglupa, or komo wood, to hard, difficult to work Eucalyptus alba, also known as poplar gum. Generic eucalyptus wood with good properties may be sold along with wood of other species in the same lot, making it difficult to obtain good quality material.