Tropical wood · Tropical America
Grumixava wood
Grumixava (Micropholis spp., family Sapotaceae) is a tropical timber from tropical America. Dry, its Janka hardness is 1,490 lbf (6,628 N), and air-dry it weighs about 41–51 lb/ft³ (657–817 kg/m³). The figures are from the USDA Forest Products Laboratory's Tropical Timbers of the World, pp. 201–202.
Other names, by country: Caimitillo (Puerto Rico), Chupón colorado, Hácano (Venezuela), Moraballi (Guyana), Riemhout, Koesiri balatarie (Surinam), Faux balata (French Guiana), Grumixava, Apixuna (Brazil), Barilla de agua (Peru), Ibirá-camby (Argentina).
Key numbers
- Janka hardness, dry
- 1,490 lbf (6,628 N)
- Green: 1,130 lbf (5,026 N)
- As printed: “Janka side hardness 1,130 lb for green material and 1,490 lb at 12% moisture content.”
- Air-dry density
- 41–51 lb/ft³ (657–817 kg/m³)
- Basic specific gravity
- 0.54–0.68 oven-dry weight, green volume
- As printed: “Basic specific gravity (ovendry weight/green volume) varying with species from 0.54 to 0.68; air-dry density 41 to 51 pcf.”
- Shrinkage, green to oven-dry
- 8.5% tangential
- Radial 5.8%, volumetric 14.3%
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 5 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 |
|---|---|---|---|
| Green | 13,630 psi (94 MPa) | 2.47 million psi (17 GPa) | 6,610 psi (46 MPa) |
| 12% MC | 18,890 psi (130 MPa) | 2.95 million psi (20.3 GPa) | 9,820 psi (68 MPa) |
| 15% MC | 19,620 psi (135 MPa) | 2.41 million psi (16.6 GPa) | 9,800 psi (68 MPa) |
| Green | 11,000 psi (76 MPa) | 1.5 million psi (10.3 GPa) | 4,850 psi (33 MPa) |
| 15% MC | 14,500 psi (100 MPa) | — | 7,100 psi (49 MPa) |
A dash means the sheet prints no value; none is filled in.
What the data sheet says
- Color, grain and texture
- Heartwood yellowto gray-brown with a somewhat pinkish tinge and sometimes with a yellowish-green hue; not clearly differentiated from the lighter colored sapwood. Texture fine to medium, uniform; grain mostly straight; luster medium; without distinctive odor or taste. Silica content of 0.2 to 0.5% is reported. Janka side hardness 1,130 lb for green material and 1,490 lb at 12% moisture content. Forest Products Laboratory toughness average for green and dry material is 128 in.-lb (5/8-in. specimen).
- Working properties
- Some species moderately difficult to saw and machine with rather rapid dulling of cutters due to silica. However, straight-grained stock yields smooth surfaces in most operations.
- Durability
- The heartwood is rated as moderately durable in resistance to white-rot fungi and very durable in resisting brown-rot fungi. Actual field experience rates this wood as moderately resistant to decay. The wood is susceptible to dry-wood termites. Resistance to marine borers is variable.
- Uses
- Furniture components, general construction, decorative veneer, turnery, flooring, millwork, interior trim. Some resemblance to hard maple and yellow birch.
- Where it grows
- West Indies and tropical America but mainly in the Guianas and Amazonia. In Surinam found in high, marsh, and savanna forests.
Quoted from Tropical Timbers of the World, pp. 201–202, a USDA Forest Products Laboratory work in the public domain.
Work it out for your project
- Rank woods for furniture with the species picker
Weigh grumixava against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.