Explanation of ratings

Green density:   The density of wood in the living tree, defined by mass divided by volume.

Air dry density:   The density of wood, defined by mass divided by volume, with a moisture content of 12 percent, which is the average for coastal capital cities around Australia.

Basic density:  
The oven-dried density of wood, defined by mass divided by volume.

Heartwood:   The inner layers of wood in growing trees that have ceased to contain living cells. Heartwood is generally darker than sapwood, but the two are not always distinguishable.

Sapwood:   The outer zone of wood in a tree, next to the bark. Sapwood is generally lighter than heartwood.

Durability class:   A standard created by the CSIRO for rating the performance of outer heartwood when placed in the ground and exposed to fungal attack, and fungal plus termite attack. Woods that have no durability rating are usually not placed in the ground. Durability classes are:
1 = Over 25 years.
2 = 15 to 25 years.
3 = 8 to 15 years.
4 = less than 8 years.

Hardness:   The rating is from the Janka hardness test that measures the force required to embed a 11.28 mm (0.444 in.) steel ball to half its diameter into the wood. It is one of the known ways to test the ability and wear. The figure presented is in kN (kilonewtons) and the higher the figure the better.