Otway Blackwood — Acacia melanoxylon
A premium furniture and joinery hardwood from the Otway Ranges in southwest Victoria. Class 3 above-ground heartwood with distinctive golden brown to dark chocolate colouring and ribbon-like figure. The flagship Australian acacia for fine furniture, musical instruments, and bench-top joinery.
Otway Blackwood products
Joinery timber and bench tops sourced from Otway Ranges mills. Decking and structural sections not commonly available — Blackwood is best suited to fine indoor work.
Technical ReferenceSummary
Otway Blackwood (Acacia melanoxylon) is the flagship Australian acacia, sourced from the temperate rainforests of the Otway Ranges in southwest Victoria. It has been the timber of choice for premium furniture, cabinetry, joinery, and musical instruments — including high-end acoustic guitars and violin backs — for over a century.
The heartwood is golden brown to dark chocolate, often with figured or ribbon-like grain that resembles walnut. Strength Group SD4 seasoned (S4 unseasoned), Joint Group JD3 (J3), F-grade F22 seasoned. Density 650 kg/m³ — moderately heavy for a furniture timber. Class 3 above-ground durability (7–15 years). Sapwood is Lyctus-susceptible. Best specified for protected interior applications where its appearance can be appreciated.
Class 3 of 4
Character & Appearance
Heartwood is golden brown to dark chocolate, with a distinctive figured grain that ranges from subtle to dramatic ribbon-like patterns. Sapwood is much paler — pale yellow to pale brown. The species is prized in furniture making for its colour, workability, and the way it polishes to a soft lustrous sheen.
Grain is generally straight to slightly wavy, though figured material with ribbon, fiddleback or birdseye patterns commands a premium. Texture is medium and uniform, machining cleanly and accepting stains, oils and lacquers exceptionally well. Holds fixings reliably. Workability is excellent — one of the easier Australian hardwoods to machine and hand-work.
Species & General Properties
Mechanical & Physical Properties
| Property | Unseasoned | Seasoned |
|---|---|---|
| Density | 1,050 kg/m³ | 650 kg/m³ |
| Janka hardness | 4.2 kN | 4.9 kN |
| Modulus of rupture (bending) | 72 MPa | 110 MPa |
| Modulus of elasticity | 12 GPa | 14 GPa |
| Maximum crushing strength | 34 MPa | 58 MPa |
| Strength Group | S4 | SD4 |
| Stress Grade (Structural No.1) | F14 | F22 |
| Joint Group | J3 | JD3 |
| Shrinkage (Total) | Value |
|---|---|
| Tangential shrinkage | 4.20 % |
| Radial shrinkage | 1.60 % |
Recommended Applications
Otway Blackwood is best specified for protected interior work where its rich colour, workability and figured grain can be appreciated. From dining tables and cabinetry to acoustic guitar backs and high-end joinery — this is the timber chosen when appearance and workability matter as much as performance.
Specification Notes
- Natural durability ratings apply to heartwood only. Sapwood is Lyctus-susceptible.
- Recommended spec wording: "Otway Blackwood (Acacia melanoxylon) heartwood — AS 5604 Class 3 above-ground durability, Strength Group SD4 seasoned, Joint Group JD3 seasoned, F-grade F22 seasoned typical."
- Internal use focus: Class 3 durability gives 7–15 years above-ground service. For unprotected exterior or wet-area applications, specify a more durable species (Spotted Gum, Blackbutt, Ironbark).
- Lyctus: sapwood susceptible. Specify Lyctus-treated material or heartwood-only for joinery applications.
- Working notes: Excellent workability. Machines, glues, finishes well. Takes polish to a lustrous sheen.
- Bushfire performance: BCA Group 4 fire rating, AS 3959 approved for BAL 12.5 and 19 zones.
References
Speccing Otway Blackwood for a project?Otway Blackwood for a project?
Premium Australian acacia from the Otway Ranges. We source on a project basis — talk to us about quantity, profile, grade (incl. figured material for feature work). Typical lead times 2–6 weeks.