GONÇALO ALVES
Jobillo / Astronium graveolens
Local Names
Tigerwood, Muiracatiara, Jobillo, Ciruelillo, Palo de Cera, Palo de Culebra, Gusanero, Gateado, Guaritá, Guasango, Ron Ron, Zorro
Distribution & Tree
Gonçalo Alves is found in the forests of southern Mexico and Central America through to Colombia, Venezuela, Brazil, Paraguay and Ecuador with a range normally up to 800m above sea level. Its commercial name arises from the high Brazilian share of exports on international markets. In Guatemala it’s known alternately as jocote de frayle in Izabal and jobillo in Peten. It’s found in soils of varying fertility in both humid and dry tropical forest. Tree diameters range from 100cm and reach a height of 25m. Except for narrow buttresses, it has a clear cylindrical bole for two-thirds or more of its height.
Wood Appearance
When fresh, the heartwood is orange or reddish-brown with irregular dark stripes. In the United Kingdom, it’s sometimes referred to as zebrawood. After exposure, the wood turns a darker brown, red, or reddish-brown with dark stripes. The dingy grayish or brownish-white sapwood, 2 to 4 in. wide, is sharply demarcated. Grain variable, straight to roey; texture fine to medium, uniform; no distinctive odor or taste. The wood often has a striking figure caused by irregular dark longitudinal bands.
Processing Properties
Gonçalo Alves is not difficult to work despite its high density, finishing smoothly and taking a high polish. The wood weathers well and is highly resistant to moisture absorption. It is difficult to glue. The use of Stellite-tipped or tungsten-carbide implements is suggested. Slicing is good. Pre-boring is necessary.
Strength & Durability
A wood density ranging from 850 to 1,280 kg/m3 is its truly an ironwood. Gonçalo Alves’ reported to have an outdoor life of 15 years. The heartwood to be very durable in resistance to both white-rot and brown-rot organisms as well as against dry wood borers and termites. It can be used in ground or with fresh water contact. It generally does not require any preservative treatment.
Wood Uses
It’s among the most sought-after heavy, durable construction timbers. Stairs, flooring, cladding and arches. It’s used for exterior and interior joinery and highly favored as a fine furniture and cabinet wood. It’s often cut for decorative veneers. It’s used for specialty items such as knife handles, brush backs, archery bows, billiard cue butts, turnery, and carving.
Ecological & Social Importance
Gonçalo Alves’ honey-yielding flowers are yellowish green. A volatile compound in its bark is thought to be an ant repellent.
Reference Species | ||||
Technical Characteristics | Gonçalo Alves | Ipê | Shagbark Hickory | |
Density | kg/m3 | 961 | 945 | 800 |
Janka Hardness | kgf | 1,026 | 1,515 | 853 |
Bending Stiffness (Modulus of Elasticity) | GPa | 16.6 | 22.1 | 14.9 |
Bending Strength (Modulus of Rupture) | MPa | 117.0 | 177.0 | 139.3 |
Crushing Strength | MPa | 74.2 | 93.8 | 63.5 |
Shrinkage, Radial | % | 4.2% | 5.9% | 7.0% |
Shrinkage, Tangential | % | 7.8% | 7.2% | 10.5% |
Shrinkage, Volumetric | % | 11.2% | 12.4% | 16.7% |
T/R Ratio | 1.9 | 1.2 | 1.5 | |
Values determined at 12% humidity |
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DENSITY
JANKA HARDNESS
BENDING STIFFNESS
BENDING STRENGTH
CRUSHING STRENGTH
SHRINKAGE
Values are for reference only and cannot be guaranteed. Wood is a natural material and physical and mechanical properties may vary depending on age, genetics, and other factors. We encourage customers to consult the references provided in the bibliography. For further explanations of wood’s key technical characteristics, an excellent resource is the Wood Database with articles on Density (average dried weight); Janka hardness; Elastic Modulus; Rupture Modulus; Crushing Strength; Radial, Tangential and Volumetric Shrinkage.