USDA Forest Service
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53705-2398
(608) 231-9200

 

Wood Technical Fact Sheet

 

 Julbernardia globiflora

Muwa

Family: Leguminosae

Other Common Names: Mchenga, Mgombo, Msima (Tanzania).

Distribution: Zambia and Tanzania, widespread in the savanna woodlands.

The Tree: Total height to 40 ft; boles 8 to 20 ft; trunk diameters 1 1/2 to 3 ft; commonly contains ring shake.

The Wood:

General Characteristics: Heartwood dark red brown, lighter towards the periphery; sapwood pale yellowish brown, 3 to 6 in. wide, distinct. Texture medium to coarse grain strongly interlocked to irregular; lustrous.

Weight: Basic specific gravity (ovendry weight/green volume) about 0.78; air-dry density 60 pcf.

Mechanical Properties: (2-cm standard)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

(%) (Psi) (1,000 psi) (Psi)

12% (40) 21,300 2,260 11,700

Janka side hardness 2,470 lb for dry material.

Drying and Shrinkage: Dries slowly with a strong tendency to warp; surface and end checking moderate. No information on kiln schedules. Shrinkage green to 12% moisture content: radial 2.9%; tangential 3.6%. Movement in service rated as medium.

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.

Preservation: Heartwood is untreatable; permeability of sapwood variable, outer zone most permeable.

Uses: Heavy construction, mining timbers, railroad crossties.

Additional Reading: (3),(5), (40)