Tropical wood · Tropical America
Duru wood
Duru (Apeiba spp., family Tiliaceae) is a tropical timber from tropical America. Dry, its Janka hardness is 250 lbf (1,112 N), and air-dry it weighs about 9–21 lb/ft³ (144–336 kg/m³). The figures are from the USDA Forest Products Laboratory's Tropical Timbers of the World, pp. 27–28.
Other names, by country: Peine de mico (Mexico), Burillo (Nicaragua), Corcho (Colombia), Cortezo (Panama), Alastioelan, Borredaballi (Surinam), Maqui-sapa (Peru), Cortica, Gargauba (Brazil).
Key numbers
- Janka hardness, dry
- 250 lbf (1,112 N)
- As printed: “Janka side hardness about 250 lb for dry material.”
- Air-dry density
- 9–21 lb/ft³ (144–336 kg/m³)
- Basic specific gravity
- 0.12–0.27 oven-dry weight, green volume
- As printed: “Basic specific gravity (ovendry weight/green volume) is very variable due to the irregular bands of soft tissue 0.12 to 0.27; air-dry density 9 to 21 pcf.”
- Shrinkage, green to oven-dry
- 6.3% tangential
- Radial 2.1%, volumetric 7.8%
One source: USDA Forest Products Laboratory, Tropical Timbers of the World (Chudnoff, 1979 edition), the only published source read for this wood
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE); crushing strength is compression parallel to the grain. The sheet collects these from published tests: it prints 2 data sets, from different tests and sources, so they can differ widely; all are shown, in the sheet's order, each at the moisture content printed beside it, never restated as 12%.
| Moisture | Bending strength (MOR) | Stiffness (MOE) | Crushing strength |
|---|---|---|---|
| 12% MC | 4,000 psi (28 MPa) | 0.67 million psi (4.6 GPa) | — |
| 12% MC | 5,950 psi (41 MPa) | 0.38 million psi (2.6 GPa) | 3,040 psi (21 MPa) |
A dash means the sheet prints no value; none is filled in.
What the data sheet says
- Color, grain and texture
- Without distinction between sapwood and heartwood, pale brown to oatmeal color; texture medium to coarse; grain straight; not highly lustrous; without distinctive odor or taste. Wood has bands of soft cottony material that may be sporatic in occurrence.
- Working properties
- The wood is easy to work in all operations but due to the bands of soft tissue, dressed surfaces are rough. Silica content is reported to be 0.03%.
- Durability
- The wood is vulnerable to attack by decay fungi.
- Uses
- The wood is used to make rafts along the eastern coast of Brazil. Suggested as an insulating material in Colombia. 1. Falla Ramirez, A. 1971?. Resultados de estudios fsico-mecn1cos de algunas maderas de la Serrana de San Lucas. Plegable Divulgativo, Division Forestal, Instituto de Desarrollo de los Recursos Naturales Renovables, Bogota.
- Where it grows
- The genus has a wide range in tropical America with the center of distribution in northern South America; found in the West Indies, southern Mexico, Central America, and southward to Brazil and Peru.
Quoted from Tropical Timbers of the World, pp. 27–28, a USDA Forest Products Laboratory work in the public domain.
Work it out for your project
- Rank woods for your project with the species picker
Weigh duru against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.