Walnut, Queensland

Queensland walnut is an Australian native hardwood timber. Its uses are mostly decorative and include furniture, plywood, turning and acoustic guitar backs and sides.

Other Names

Australian Walnut, Oriental Wood, Walnut Bean, Black Nut, Black Walnut, Cryptocarya Palmerstonii

Botanical Name

Endiandra palmerstonii

Common Form
Veneer
Species Type
Hardwood
  • Overview

    • Queensland walnut is a large rainforest tree growing to a height of around 35 metres with a stem diameter of up to 1.8 metres. It is restricted to the coastal tablelands of North Queensland, between Innisfail and Atherton, where it is the dominant rainforest tree species.

    The heartwood of the species varies in colour, but is usually greyish-brown with streaks of chocolate brown, black or pink. The sapwood, up to 100 millimetres wide, is pale yellow. Queensland walnut timber exhibits medium texture with a moderate natural lustre and shallow open pores. Grain is close and even, usually interlocked, and commonly wavy. This results in a wide variety of figure effects, especially attractive on quarter-sawn surfaces.

    Uses for Queensland walnut are mainly decorative and include plywood, veneers, shop and office fixtures, turnery, and musical instruments - notably guitar backs and sides. Queensland walnut is reported to have higher than usual electrical insulation properties, and may be suitable for some types of electrical enclosure applications.

    Timber produced from Queensland walnut has a life expectancy of between five and seven years (for in-ground and above ground applications, respectively). The timber is not termite-resistant, and untreated sapwood is susceptible to borer attack. Sapwood (but not heartwood) is readily impregnated with preservatives. Queensland walnut is recommended for use in continuously dry situations that are under cover, well ventilated, clear of the ground and fully protected from the weather and other dampness.

    Commercial availability of Queensland walnut timber is currently very limited, due to World Heritage listing of the main sites in which it occurs.

    Shrinkage

    Very Low Low Medium High Very High
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    Tangential : Provides a simplified rating for tangential shrinkage. This is the measure of the percentage reduction in dimension from the unseasoned to 12% moisture content condition.
    4.60%

    Radial : Radial shrinkage is perpendicular to the growth rings. It is shrinkage in the direction towards the centre of the tree. Measurement is % value
    2.10%

    Unit Movement Tangential: This is the percentage of dimensional change for each 1% moisture content change between about 3% moisture content and the fibre saturation point for the particular species.
    0.32%

    Unit Movement Radial: This is the percentage of dimensional change for each 1% moisture content change between about 3% moisture content and the fibre saturation point for the particular species.
    0.19%

    Strength Group Strength groups are given for unseasoned (S1-S7) and seasoned (SD1-SD8) timber in accordance with AS 2878. S1 and SD1 yield the highest strength and stiffness whereas S7 and SD8 yield the lowest.

    Very High

    High

    Reasonably High

    Medium High

    Medium

    Reasonably Low

    Low

    Very Low

    Unseasoned:

    S1

    S2

    S3

    S4

    S5

    S6

    S7

    S8
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    Seasoned:

    SD1

    SD2

    SD3

    SD4

    SD5

    SD6

    SD7

    SD8
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    Stress Grade A stress grade is defined in AS 1720 as the classification of timber for structural purposes by means of either visual or machine grading. The stress grade indicates the basic working stresses and stiffnesses to be used for structural design purposes. Measured in MPa.

    Structural
    No. 1    		 Structural
    No. 2    		 Structural
    No. 3    		 Structural
    No. 4    		 Structural
    No. 5

    Unseasoned:

    F11

    F8

    F7

    F5

    F4

    Seasoned:

    F17

    F14

    F11

    F8

    F7

    Density per Standard Seasoned density is based on moisture content of 12%. Unseasoned density is an approximation as it depends on the moisture content at the time of measurement. Measured kg/m3.

    Seasoned:

    680kg/m3

    Unseasoned:

    900kg/m3

    Joint Group The joint group is a classification of the strength of a species in joint design. The values are from 1 (very high strength) to 6 (very low strength).

    Very High

    High

    Reasonably High

    Medium

    Low

    Very Low

    Unseasoned:

    J1

    J2

    J3

    J4

    J5

    J6
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    Seasoned:

    JD1

    JD2

    JD3

    JD4

    JD5

    JD6
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    Colour The colour of seasoned heartwood can vary between species and often within a species. The information provided should be used as a general guide only. In most cases, the colour of sapwood is either a lighter shade of the heartwood or a white/cream colour.

      White, yellow, pale straw to light brown Pink to pink brown Light to dark red Brown, chocolate, mottled or streaky
       
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    Mechanical Properties

    Modulus of Rupture - Unseasoned: This property is a measure of maximum stress which timber can momentarily sustain when loaded slowly and continuously as a beam. Measured in MPa.

    Modulus of Rupture - Seasoned: This property is a measure of maximum stress which timber can momentarily sustain when loaded slowly and continuously as a beam. Measured in MPa.

    Modulus of Elasticity - Unseasoned: This property is of importance in determining the deflection of a beam under load — the greater the stiffness, the less the deflection. Measured in GPa.

    Modulus of Elasticity - Seasoned: This property is of importance in determining the deflection of a beam under load — the greater the stiffness, the less the deflection. Measured in GPa.

    Maximum Crushing Strength - Unseasoned:

    Also referred to as compression strength. This property measures the ability of the timber to withstand loads applied on the end grain. Measured in MPa.

    Maximum Crushing Strength - Seasoned: Also referred to as compression strength. This property measures the ability of the timber to withstand loads applied on the end grain. Measured in MPa.

    Impact - Unseasoned: Provides the Izod value, which is the energy taken in joules (J) to fracture the timber.

    Impact - Seasoned: Provides the Izod value, which is the energy taken in joules (J) to fracture the timber.

    Toughness - Unseasoned: This is a measure of timber’s ability to resist shocks and blows, and is synonymous with impact strength. It is measured in Nm.

    Toughness - Seasoned: This is a measure of timber’s ability to resist shocks and blows, and is synonymous with impact strength. It is measured in Nm.

    Hardness - Unseasoned: Refers to the Janka hardness test and is a measure of timber’s resistance to indentation.

    Hardness - Seasoned: Refers to the Janka hardness test and is a measure of timber’s resistance to indentation.

    Durability

    Low Moderate Reasonably High High
    (0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)

    In-Ground: Durability is defined as the inherent resistance of a timber species to decay, or to insect or marine borer attack. All references to durability refer to the heartwood only. A scale of low to high (durability class 4 = low; 1 = high) has been adapted for above and in-ground durability.

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    (0 - 7 yrs) (7 - 15 yrs) (15 - 40 yrs) (More than 40 yrs)

    Above ground: Durability is defined as the inherent resistance of a timber species to decay, or to insect or marine borer attack. All references to durability refer to the heartwood only. A scale of low to high (durability class 4 = low; 1 = high) has been adapted for above and in-ground durability.

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    (0 - 20 yrs, usually < 5) (21 - 40 yrs) (41 - 64 yrs) (More than 60 yrs)

    Marine Borer Resistance: Indicates whether a species is resistant (R) or not resistant (NR) to marine borer attack.

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    Lyctid Borer Susceptibility: Indicates whether a species is susceptible (S) or not susceptible (NS) to lyctid borer attack.

    Susceptible

    Lyctid Borer Susceptibility - Other:

    Termite Resistance: Indicates whether a species is resistant (R) or not resistant (NR) to termites.

    Not Resistant

    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: A measure of the tendency of a material to ignite measured on a scale of 0 – 20. An index of 0 indicates that the material did not ignite during the 20 minutes that the test takes. An index of 20 indicates that the material ignited in the first minute.
    0 1 2 3 4 5 6 7 8 9 10

    EFH Spread-of-Flame Index: This is a material's propensity to burn rapidly and spread flames based on a scale of 0 to 10 where 0 means that the materials will not cause flames to reach the ceiling and 10 indicates that the material could be expected to cause flames to reach the ceiling of a room within 10 seconds of ignition.

    EFH Smoke-Developed Index:This is a measure of the concentration (measured by optical density) of smoke a material emits as it burns. It is based on an arbitrary scale of 0 to 10. The higher the index, the greater the hazard from smoke is likely to be.
    1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible

    Fire Properties Group
    Number:

    Group Number - Other:
    3 if used on MDF or particleboard ≥12mm; veneer thickness 0.6-0.85mm

    Average Specific Extinction Area: This value is determined by the volume of smoke measured over the mass loss of the tested sample per test carried out in accordance with ‘Cone Calorimeter Test’ AS/NZS 3837. It is measured in units of m2/kg.
    <250

    Bushfire Resistance: Naturally bushfire-resisting timbers are those with inherent bushfire-resisting properties. Some species have been tested and a number are in the process of being tested and are measured by Bushfire Attack level (BAL). BAL -12.5: Ember attack, BAL – 19: Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 12.5 and 19 kWm3, BAL – 29: Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 19 and 29 kWm3.
    BAL 12.5 and 19 – Door and window joinery only
    Appearance

    The heartwood of this species is variable in colour, but usually greyish brown with streaks of chocolate brown, black or pink. Sapwood is a pale yellow, and up to 100 millimetres wide. Queensland walnut grain is close and even with occasional waves resulting in a wide variety of figure effects, especially attractive on quarter-sawn surfaces.

    Common Applications

    Uses for Queensland walnut are mainly decorative and include plywood, furniture, shop and office fixtures, turnery, as well as guitar backs and sides.

    Workability

    Queensland walnut is only moderately hard. It lends itself to steam bending and can be worked with hand tools. The timber machines and sands well, but can be abrasive to machine cutters due to its high silica content. No difficulty has been experienced with the use of standard fittings and fastenings. Queensland walnut will readily accept most coatings including paint, stains, polishes and glues. Oiled surfaces are particularly impressive. An unpleasant odour experienced while working Queensland walnut is not detectable in the dry timber.

     

    Origin of timber
    QLD
    Readily Available
    NSW
    Queensland Walnut is usually only available as a veneer. Anecdotal evidence suggests that supplies of this timber are becoming scarce.
    Source of timber
    Native Forest

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