Tropical wood · Africa
Muwa wood
Muwa (Julbernardia globiflora, family Leguminosae) is a tropical timber from Africa. Dry, its Janka hardness is 2,470 lbf (10,987 N), and air-dry it weighs about 60 lb/ft³ (961 kg/m³). The figures are from the USDA Forest Products Laboratory's Tropical Timbers of the World, pp. 435–436.
Other names, by country: Mchenga, Mgombo, Msima (Tanzania).
Key numbers
- Janka hardness, dry
- 2,470 lbf (10,987 N)
- As printed: “Janka side hardness 2,470 lb for dry material.”
- Air-dry density
- 60 lb/ft³ (961 kg/m³)
- Basic specific gravity
- 0.78 oven-dry weight, green volume
- As printed: “Basic specific gravity (ovendry weight/green volume) about 0.78; air-dry density 60 pcf.”
- Shrinkage, green to 12% moisture content
- 3.6% tangential
- Radial 2.9%
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 one data set, each at the moisture content printed beside it, never restated as 12%.
| Moisture | Bending strength (MOR) | Stiffness (MOE) | Crushing strength |
|---|---|---|---|
| 12% MC | 21,300 psi (147 MPa) | 2.26 million psi (15.6 GPa) | 11,700 psi (81 MPa) |
A dash means the sheet prints no value; none is filled in.
What the data sheet says
- Color, grain and texture
- Heartwood dark red-brown, lighter towards the periphery; sapwood pale yellowish brown, 3-6 in. wide, distinct. Texture medium to coarse; grain strongly interlocked to irregular; lustrous.
- Working properties
- Difficult to work with hand and machine tools, rapid blunting of cutters, grain tears in planing and molding, slow feed speeds are suggested, unsatisfactory for turning, moderate steam-bending properties.
- Durability
- Heartwood is rated as durable but liable to termite attack. Sapwood susceptible to attack by powder-post beetles.
- Uses
- Heavy construction, mining timbers, railroad crossties.
- Where it grows
- Zambia and Tanzania, widespread in the savanna woodlands.
Quoted from Tropical Timbers of the World, pp. 435–436, a USDA Forest Products Laboratory work in the public domain.
Work it out for your project
- Rank woods for ground contact with the species picker
Weigh muwa against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.