Goncalo alves (Astronium graveolens) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Goncalo alves |
|---|---|
| Janka side hardness, 12% moisture | 2,160 lbf (9,608 N) |
| Janka side hardness, green | 1,910 lbf |
| Hardness rank | harder than 152 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 62.5 lb/ft³ (1,001 kg/m³)* |
| Weight per board foot (12%) | 5.21 lb* |
| Specific gravity (ovendry weight, green volume) | 0.84 |
| Specific gravity at 12% moisture | 0.89* |
| Bending strength (modulus of rupture), 12% | 16,600 psi |
| Stiffness (modulus of elasticity), 12% | 2.23 million psi |
| Crushing strength (compression parallel to grain), 12% | 10,320 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 4.0% / 7.6% / 10.0% |
| Tangential / radial shrinkage ratio | 1.9 |
| Dimensional change per 1% moisture (radial / tangential) | not reported |
| Heartwood decay resistance | very resistant |
What it is
Goncalo alves is the wood of Astronium graveolens and A. fraxinifolium, which range from southern Mexico through Central America into the Amazon basin; most imports have come from Brazil. In the flooring and decking trade the same wood is sold as tigerwood, after its striped figure.
Freshly cut heartwood is russet, orange-brown or reddish brown to red, with narrow to wide irregular stripes of medium to very dark brown. After exposure to air it becomes brown, red or dark reddish brown with nearly black stripes. The sapwood is greyish white and sharply marked off. The texture is fine to medium and uniform, and the grain varies from straight to interlocked and wavy.
Working properties
The Handbook says goncalo alves turns readily, finishes very smoothly and takes a high natural polish. Its heartwood is highly resistant to moisture absorption, and the dense pigmented stripes can make gluing difficult, so wipe joints with a solvent and glue promptly after machining. Its strength is considerably higher in most respects than that of any US species; in our data it has 2,160 lbf of Janka hardness and 16,600 psi of bending strength.
The heartwood is very durable, resistant to both white-rot and brown-rot fungi, and in the very resistant class of Table 14-1. Tangential shrinkage is moderate for such a dense wood at about 7.6%, which helps it stay flat as decking. Like other oily tropical decking, it is usually left to weather or treated with a penetrating oil rather than a film finish.
Weight and density
At 12% moisture content goncalo alves weighs about 62.5 lb per cubic foot (estimated from its specific gravity and shrinkage), so one board foot (144 cubic inches) weighs about 5.21 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 14.3 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 18.2 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Goncalo alves | 2,160 | 62.5* | 16,600 | 2.23 | 7.6 | very resistant |
| Ipe | 3,680 | 64.0† | 25,400 | 3.14 | 8.0 | very resistant |
| Courbaril (jatoba) | 2,350 | 53.8* | 19,400 | 2.16 | 8.5 | resistant |
| Purpleheart | 1,860 | 49.8* | 19,200 | 2.27 | 6.1 | very resistant |
| Jarrah | 1,910 | 54.0† | 16,200 | 1.88 | 11.0 | very resistant |
| Black walnut | 1,010 | 38.5 | 14,600 | 1.68 | 7.8 | resistant |
Uses
Despite its strength, the Handbook notes it is imported mainly for its beauty. In the United States it is valued for archery bows, billiard cue butts, brush backs, cutlery handles, turnery and carving. As tigerwood it is widely sold for exterior decking and interior flooring.
Frequently asked questions
Is tigerwood the same as goncalo alves?
Yes. Tigerwood is a trade name for Astronium species, which the Wood Handbook covers as goncalo alves.
Is tigerwood good for decking?
It is a dense, very decay-resistant wood with 2,160 lbf of Janka hardness. Pre-drill fixings, allow it to acclimatise, and expect the colour to weather to grey unless oiled.
How hard is goncalo alves?
The Wood Handbook gives 2,160 lbf (9,608 N) at 12% moisture content, about 1.6 times that of white oak.
Is goncalo alves hard to glue?
It can be, because the dense pigmented stripes and the heartwood resist absorbing moisture. Fresh surfaces and a solvent wipe help.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 24 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.