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Clicking any heading in the main data area (at right) will scroll the page back to this top position. Use the following links to jump to the associated section in the main data. Blunting Effect Boring Carving Comments Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Light-Induced Color Change Luster Mortising Moulding Movement in Service Nailing Natural Durability Natural Growth Defects Numerical Data Odor Painting Planing Polishing Product Sources References Regions of Distribution Resistance to Impregnation Resistance to Splitting Response to Hand Tools Routing & Recessing Sanding Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Texture Toxicity Trade Name Tree Size Turning Varnishing Veneering Qualities Scientific Name Grevillea robusta Trade Name Silky oak Family Name Proteaceae Common Names Australian silky oak, Australian silky-oak, Carvalho sedoso, East African silky oak, Gravilea, Greirllea, Grevilea, Grevilia, Grevillea, Helecho, Kawilia, Lacewood, Pino rojo, Roble de pelota, Roble de seda, Roble redoso, Silk oak grevillea, Silky oak, Southern silky oak, Tuggan-tuggan Regions of Distribution North America, Oceania and S.E. Asia Countries of Distribution  [VIEW MAP] Australia, South Africa, United States Common Uses Agricultural implements, Balusters, Bedroom suites, Boxes and crates, Brush backs & handles, Building construction, Building materials, Cabinetmaking, Casks, Chairs, Chests, Coffins, Concealed parts (Furniture), Concrete formwork, Construction, Cooperages, Desks, Dining-room furniture, Domestic flooring, Dowell pins, Dowells, Drawer sides, Excelsior, Factory flooring, Fine furniture, Floor lamps, Flooring, Flooring: industrial heavy traffic, Furniture , Furniture components, Furniture squares or stock, Furniture, Hatracks, Heavy construction, Interior construction, Joinery, Kitchen cabinets, Light construction, Living-room suites, Moldings, Office furniture, Packing cases, Paneling, Parquet flooring, Particleboard, Plywood corestock, Plywood, Pulp/Paper products, Pulpwood, Radio - stereo - TV cabinets, Rustic furniture, Stairworks, Toys, Turnery, Vats, Vehicle parts, Veneer, Veneer: decorative Environmental Profile Endangered Extinct Abundant/Secure Status has not been officially assessed Distribution Overview Native to eastern Australia but planted extensively as a shade tree for coffee and tea plantations and as an ornamental in tropical and subtropical regions. Can be found in Tanganyika and some areas of the U.S. It has gained widespread popularity in warm temperate, subtropical and tropical highland regions of many countries, originally as a shade tree for tea and coffee and more recently as an agroforestry tree for small farms. It provides economically valuable products including timber, poles, firewood and leaf mulch; it is easy to propagate and establish and is relatively free of pests and diseases; its proteoid roots help it grow in low-fertility soils; it does not compete strongly with adjacent crops; and it tolerates heavy pruning of its roots and branches. The natural habitat of G. robusta is in northern New South Wales and southern Queensland, Australia, where it occurs from the east coast to as far west as the Bunya Mountains, Queensland, up to an altitude of 1120 m. Heartwood Color Red Brown Pink Yellow Purple Orange Reddish brown Pale brown Brown Yellow to golden-yellow to orange Red Pink when freshly cut The heartwood is a distinct pink or light red when freshly cut, darkening to pale or red-brown upon drying. Sapwood Color White Yellow Pink Red Brown White to yellow Well defined Straw colored to grayish-white Same as heartwood Clearly differentiated from the heartwood Grain Figure Rays (figure) Straight Wavy Distinct (figure) Closed Even Mottled (figure) Stripe (figure) Growth rings (figure) Rays figure Straight Wavy Distinct figure Striped figure Figure shows mottle Occasionally wavy Clear growth rings (figure) Broad rays and alternating darker and lighter colored bands combine to form a woven pattern which gives Silky-oak a very striking figure. Texture Fine Medium Very fine Medium coarse to coarse Medium Coarse Fair to medium coarse The wood is diffuse porous, and the texture is described as fairly coarse. Luster Medium High Low Lustrous Rays are highly lustrous, but background wood tissue is rather dull in appearance. Natural Growth Defects Gum/resin streaks Gum and mineral deposits Natural Durability Susceptible to insect attack Resistant to termites Non-resistant to powder post beetles Durable Moderately durable Very durable Resistant to powder post beetles Perishable Non-resistant to termites Non-durable Moderately durable Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Non durable Susceptible to marine borer attack Susceptible to attack from termites (Isoptera) Resistant to attack from termites (Isoptera) Pinworms (ambrosia beetles) may be present in the felled log Durable Moderately resistant to termite (Isoptera) attack Moderately resistant to attack by termites Moderately resistant to attack by pinhole borers Moderately resistant to attack by marine borers Heartwood is susceptible to wood staining fungal attack Odor No specific smell or taste Light-Induced Color Change Darker Toxicity Some toxic effects Dermatitic effects Material in the green or dry condition may cause skin irritation in some individuals. Finished wood is safe to handle Kiln Schedules Dry at a slow speed UK=C US=T3C2/T3C1 Fr=3 UK=A US=T2D4/T2D3 Fr=1 T3 - C2 (4/4); T3 - C1 (8/4) US Kiln Drying Rate (in days) is rather slow Kiln Drying Rate (in days) is fairly rapid Drying Defects Checking Splitting Distortion Resin Exudation Moderate surface checking Moderate end spitting Moderate twist/warp Slight twist/warp Slight surface checking Severe end splitting 1 inch (2.5 cm) thick boards are relatively easy to air-dry. There is some tendency for thicker stock to distort, check, and end-split especially if boxed heart is present. Honeycombing and twisting may also occur under harsh kiln-drying conditions. Ease of Drying Fairly Easy Moderately Difficult to Difficult Variable Gum Exudation Rapidly Thick Stock Requires Care Moderate Mild drying schedule recommended Easy Dries slowly Material containing boxed heart has a high tendency to degrade during seasoning Kiln Drying Rate Naturally dries quickly Slow (18-28 days for boards < 32 mm, to 52-84 days for boards >= 63 mm) Fairly rapid (11-17 days for boards under 32 mm, to 31-51 days for boards greater than 63 mm) Tree Size Trunk diameter is 100-150 cm Tree height is 30-40 m Tree height is 20-30 m Tree height is 50-60 m Tree height is 40-50 m Bole length is 20-30 m Bole length is 10-20 m Tree height is 10-20 m Trunk diameter is 150-200 cm Sapwood width is 10-15 cm Sapwood width is 5-10 cm The species is often displaced on favorable growing sites by Eucalyptus, which consists of numerous species some of the largest hardwoods. Product Sources Silky oak is costly on the US market because of transportation costs and special processing costs required to maximize its figure. The material is available in adequate supplies in its native Australia. Comments Deposits and Other Growth Features Silky-Oak is closely similar to American mahogany (Swietenia ) in most strength properties. It is rated much weaker than all the true Oaks, but its strength properties are adequate for use in fine furniture. Vessels contain red deposits, and some trees contain small knots and numerous gum streaks Blunting Effect Little Moderate Boring Fair to good results Fairly easy to very easy Very good results Moderately easy Easy The timber has very good woodworking properties. It responds well to hand and machine tools in boring, moulding, mortising and all woodworking operations to produce clean surfaces. It works readily with both hand and machine tools. Carving Fair to Good Results Fairly Easy to Very Easy Very Good to Excellent Results Good carving characteristics Cutting Resistance Easy to saw Fairly Difficult to Very Difficult to saw Cutting Resistance with green wood is easy Cutting Resistance with dry wood is easy Cutting Resistance with dry wood is moderate Green material saws easily, but sawteeth may become clogged by gum. Seasoned wood has better sawing properties. Gluing Fairly Easy to Very Easy Fair to Good Results Moderate gluing properties Mortising Fair to Good Results Fairly Easy to Very Easy Finishes well Moderately easy to mortise Easy to mortise Moulding Fair to Good Results Fairly Easy to Very Easy Good finishing results Easy to mould Moulding ease is moderate Movement in Service Excellent Stability - Small Movement Fair to Good Stability - Medium Movement Medium The timber has medium dimensional stability after manufacture. Nailing Fairly Easy to Very Easy Fair to Good Results Fairly Difficult to Very Difficult Poor to Very Poor Results Nails hold poorly Holds satisfactorily Holds nails well Good nailing qualities Easy to nail Silky-Oak has good nailing qualities and can accept even rather large diameter fasteners without splitting. Planing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Ease of planing is moderate Easy to plane Planes well, to a good finish Planes to a satisfactory finish Fair planing properties Dominant rays tend to cause chipping during planing operations, but silky-oak is more pleasant to work with than most of the true Oaks because it is less dense. Resistance to Impregnation Resistant heartwood Permeable sapwood