Tallowwood is an extremely hard, durable and versatile Australian native hardwood species. Its timber products are suitable for a wide range of applications.
Tallowwood is a moderate to large tree occurring in wet sclerophyll forests of coastal regions from the Hunter River district of New South Wales to Maryborough and Fraser Island, Queensland.
The heartwood of this species ranges in colour from pale to dark yellow-brown, with occasional tinges of olive green. Sapwood is a whitish colour. The texture of tallowwood timber is moderately coarse, generally with interlocked grain. Unusually for a eucalypt species, tallowwood is free of gum veins. Figure is lacking but the timber possesses a distinctive lustre and ‘greasy’ appearance.
Tallowwood timber products exhibit exceptional durability in both in-ground and aboveground applications, where life expectancy is greater than 25 and 40 years, respectively. Although tallowwood is highly resistant to decay and will withstand damp and wet conditions quite well, its sapwood is susceptible to lyctid borer (powder post beetle) attack. Untreated timber of this species is equivalent to ‘fire retardant treated timber’ when tested in accordance with AS/NZS 3837.
Historically, tallowwood has been used for bearings, mallet heads, mauls, wheel spokes, and tool handles. Current engineering applications include wharf and bridge construction (as sawn and round timber), railway sleepers, cross-arms, poles, piles and mining timbers. Construction uses range from unseasoned framing to dressed timber cladding, internal and external flooring, linings and joinery. Tallowwood is also used in fencing, landscaping and the construction of retaining walls. Decorative uses include outdoor furniture, turnery and joinery. Other applications include boat building, the construction of coaches, carriages and agricultural machinery, and structural plywood.
Shrinkage
Very Low | Low | Medium | High | Very High | |
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Tangential : |
6.10%
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Radial : |
3.70%
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Unit Movement Tangential: |
0.37%
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Unit Movement Radial: |
0.28%
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Strength Group
Very High |
High |
Reasonably High |
Medium High |
Medium |
Reasonably Low |
Low |
Very Low |
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Unseasoned: |
S1 |
S2 |
S3 |
S4 |
S5 |
S6 |
S7 |
S8 |
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Seasoned: |
SD1 |
SD2 |
SD3 |
SD4 |
SD5 |
SD6 |
SD7 |
SD8 |
|
Stress Grade
Structural No. 1 |
Structural No. 2 |
Structural No. 3 |
Structural No. 4 |
Structural No. 5 |
|
Unseasoned: |
F27 |
F17 |
F14 |
F11 |
F8 |
Seasoned: |
F34 |
F27 |
F22 |
F17 |
F14 |
Density per Standard
Seasoned: |
990kg/m3
|
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Unseasoned: |
1200kg/m3
|
Joint Group
Very High |
High |
Reasonably High |
Medium |
Low |
Very Low |
|
Unseasoned: |
J1 |
J2 |
J3 |
J4 |
J5 |
J6 |
---|---|---|---|---|---|---|
Seasoned: |
JD1 |
JD2 |
JD3 |
JD4 |
JD5 |
JD6 |
Colour
White, yellow, pale straw to light brown | Pink to pink brown | Light to dark red | Brown, chocolate, mottled or streaky | |
Mechanical Properties
Modulus of Rupture - Unseasoned: |
87
|
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Modulus of Rupture - Seasoned: |
137
|
Modulus of Elasticity - Unseasoned: |
14
|
Modulus of Elasticity - Seasoned: |
18
|
Maximum Crushing Strength - Unseasoned: |
48
|
Maximum Crushing Strength - Seasoned: |
76
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Impact - Unseasoned: |
20
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Impact - Seasoned: |
18
|
Toughness - Unseasoned: |
Medium - 15 - 24 Nm
|
Toughness - Seasoned: |
Medium - 15 - 24 Nm
|
Hardness - Unseasoned: |
7.1
|
Hardness - Seasoned: |
8.6
|
Durability
Low | Moderate | Reasonably High | High | |
(0 - 5 yrs) | (5 - 15 yrs) | (15 - 25 yrs) | (more than 25 yrs) | |
In-Ground: |
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(0 - 7 yrs) | (7 - 15 yrs) | (15 - 40 yrs) | (More than 40 yrs) | |
Above ground: |
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(0 - 20 yrs, usually < 5) | (21 - 40 yrs) | (41 - 64 yrs) | (More than 60 yrs) | |
Marine Borer Resistance: |
Lyctid Borer Susceptibility: |
Susceptible |
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Lyctid Borer Susceptibility - Other: |
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Termite Resistance: |
Resistant
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Fire Properties
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |
EFH Ignitibility: |
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
EFH Spread-of-Flame Index: |
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EFH Smoke-Developed Index: |
Critical Radiance Flux - Lower: |
>2.2 and <4.5 |
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Critical Radiance Flux - Higher: |
≥4.5 |
Smoke Development Rate: |
<750
|
1 - non-combustible | 2 - reasonably non-combustible | 3 - slightly combustible | 4 - combustible | |
Fire Properties Group |
Average Specific Extinction Area: |
<250
|
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Bushfire Resistance: |
BAL 12.5 and 19 – All AS3959 required applications
|
Tallowwood heartwood ranges from pale to dark yellow-brown, in contrast to its typically whitish sapwood. The texture of the timber is moderately coarse, generally with an interlocked grain relatively free of gum veins. Figure is lacking, but tallowwood has a distinctive lustre and greasy appearance.
Historically, tallowwood has been used for bearings, mallet heads, mauls, wheel spokes, and tool handles. Current engineering applications include wharf and bridge construction (as sawn and round timber), railway sleepers, cross-arms, poles, piles and mining timbers. Construction uses range from unseasoned framing to dressed timber cladding, internal and external flooring, linings and joinery. Tallowwood is also used in fencing, landscaping, and the construction of retaining walls. Decorative uses include outdoor furniture, turnery and joinery. Other applications include boat building, the construction of coaches, carriages and agricultural machinery, and structural plywood.
Tallowwood is very hard (rated 1 on a 6-class scale) in relation to indentation, yet is relatively easy to work with hand tools due to the timber’s natural greasiness – hence the species’ common name. It machines and turns well, readily accepts paint, stain and polish, and is amenable to the use of standard fittings and fastenings. Pre-drilling is recommended for nailing and screwing. Numerous extractives render tallowwood difficult to bond satisfactorily, although success has been reported with the use of polyurethane glues.