Acacia Koa (Koa)

Scientific Name
Acacia koa

Trade Name
Koa

Family Name
Leguminosae

Common Names
Koa

Regions of Distribution
Oceania and S.E. Asia

Countries of Distribution  [VIEW MAP]
Hawaii [US]

Common Uses
Bent Parts, Boat building, Building materials, Canoes, Core Stock, Decorative veneer, Drum sticks, Excelsior, Figured veneer, Gunstocks, Interior construction, Joinery, Lifeboats, Musical instruments , Novelties, Organ pipes, Paneling , Piano keys, Pianos , Plain veneer, Rifle stock, Shipbuilding, Sounding boards, Sporting Goods, Veneer, Violin bows, Violin, Wainscotting, Xylophones

Environmental Profile

Distribution Overview
Found exclusively on the Hawaiian Islands, Koa trees reach a height of 100 feet with a diameter of 4 feet. It grows at most elevations on the islands, but grows best in areas of heavy rainfall form 3,000 to 6,000 feet. It is the most conspicuous tree growing between the low, open dry forest and the wet ohia forest, and is generally quite adaptable to a variety of climates.

Heartwood Color

The wood yellows quickly in sunlight, which adversely affects its exterior performance

Sapwood Color

Grain

Attractive patterns

Texture

Luster

Natural Durability

Odor

Kiln Schedules

Drying Defects

Problems generally only with thicker stock

Ease of Drying

Tree Size

The trees are very hardy and can survive under almost any environmental condition

Product Sources
Supplies of Koa are available on the U.S. market in the form of lumber and veneers. Prices are in the high range.

Comments
Excellent for musical instruments because of its high resonant properties. Hawaiian ukeleles are made exclusively from koa wood. Trees that grow at high exposed areas produce the best figured wood, and the veneer form of Koa is highly valued for fine furniture because of its fiddleback figure and high finish it takes. Koa wood is similar to Black walnut (Juglans nigra)

Blunting Effect

Boring

Carving

Cutting Resistance

Interlocked grain. Keep tools sharp to prevent tearouts

Gluing

Gluing properties are variable, but they are generally poor

Mortising

Moulding

Movement in Service

Nailing

Planing

Wood containing curly grain may require a cutting angle of 20 degrees for best results

Resistance to Impregnation

Very resistant

Response to Hand Tools

Routing & Recessing

Screwing

Good screw holding properties

Turning

Polishing

Staining

Varnishing

Strength Properties

Numerical Data

References
Boone, R.S., C.J. Kozlik, P.J. Bois and E.M. Wengert. 1988. Dry Kiln Schedules for Commercial Woods: Temperate and Tropical. USDA, Forest Service, Forest Products Laboratory, General Technical Report FPL-GTR-57, Madison, Wisconsin.

Constantine, Jr. A.J. 1975. Know your Woods: A Complete Guide to Trees, Woods, and Veneers. Revised Edition. Revised by Harry J. Hobbs. Charles Scribner and Sons, New York.

Imported Wood Purchasing Guide: A Comprehensive Purchasing Reference for Imported Woods. 1992. 20th Edition. International Wood Trade Publication, Inc. 1235 Sycamore View, Box 34908, Memphis Tennessee.

Kaiser, J. 1990. Wood of the Month: Koa – The Wood from the Hawaiian Islands. Wood & Wood Products, January 1990, Page 48.

Keating, W.G., Bolza, E.,1982,Characteristics properties and uses of timbers. South East Asia, Northern,Australia and the Pacific,C.S.I.R.O. Div. Chemical Technology,Inkata Press,1

Kline, M. 1982. Acacia koa – Koa. In A Guide to Useful Woods of the World. Flynn Jr., J.H., Editor. King Philip Publishing Co., Portland, Maine. 1994. Page 12.

Lincoln, W.A. 1986. World Woods in Color. Linden Publishing Co. Inc., Fresno, California.