WA blackbutt
Eucalyptus patensWA blackbutt has the common name 'yarri'. WA blackbutt is usually a tall tree up to 45 m in height, with diameter at breast height to 1.8 m and a relatively large straight bole. On less favourable, particularly swampy sites, it is a smaller tree of poor form. It has a natural distribution that coincides closely with that of jarrah (E. marginata), from near Perth in the north to Albany on the south coast.
Wood
description [more
info]
Heartwood is pale yellowish-brown, and the sapwood is sufficiently
paler to be distinguishable.
Wood
density [more
info]
Green density is about 1120 kg/m3, air-dry density about 850 kg/m3,
and basic density about 690 kg/m3.
Shrinkage [more
info]
Tangential and radial shrinkage before reconditioning are 10.0
and 5.0 per cent respectively, and after reconditioning 7.0 and 3.5 per
cent respectively.
Workability [more
info]
The timber is relatively easy to work, although
interlocked grain can make it difficult.
Durability [more
info]
Durability Class based on the CSIRO 1996 ratings
is 2 for decay, and 4 for decay + termites. Sapwood is Lyctus-susceptible.
Strength
group and properties [more
info]
Green and dry strength groups are S4 and SD5. The more important strength
properties are given in the table below.
Property |
Units |
Green |
Dry |
|---|---|---|---|
Modulus of Rupture |
MPa |
66 |
99 |
Modulus of Elasticity |
MPa |
12000 |
13000 |
Max Crushing Strength |
MPa |
37 |
65 |
Hardness |
KN |
5.5 |
6.9 |
Uses [more
info]
Blackbutt's main use
has been in flooring, although in the past it was used for general construction,
case manufacture, sleepers, flooring and panelling.
Availability [more
info]
Availability is limited, because a large part of the resource
is now conserved in stream reserves. The timber is available in small
quantities in Western Australia.









