Among botanists and other scientists interested in trees and the wood they yield, Wenge is known as Millettia laurentii. A closely related species is M. stuhlmannii, sometimes sold as Panga Panga, which yields a wood that is similar in appearance, however it is native to eastern Africa.
Millettia laurentii is native to central-west Africa, being harvested from the eastern parts of Cameroon, Equatorial Guinea and Gabon and the western parts of the Central African Republic, the Congo Republic, and the Democratic Republic of the Congo. Gabon and Congo are by far the largest exporters of M. laurentii. Cameroon exports much smaller quantities of sawn lumber but actual logs of Millettia laurentii require a special license to export from the country. The other nations in which this species grows export smaller amounts of material. This is due both to the existence of other viable resources, such as petroleum in Equatorial Guinea, as well as civil unrest and violence in both the Central African Republic and the Democratic Republic of the Congo.
For the sake of simplicity and common understanding, I will refer to M. laurentii from this point forward as Wenge.
I have written about Wenge in the past in reference to making a bowl from a larger blank. This post will serve to update the information to the most current as of 2017 and to standardize the format to be consistent with other posts about specific turning woods.
Wenge is an interesting wood for many reasons, but one of the more unusual characteristics of this wood is that the heartwood is a pale yellow when freshly cut but it then fairly quickly darkens to its signature appearance: medium brown, sometimes with a reddish or yellowish hue, with nearly black streaks throughout. This striped appearance is the primary motive for woodworkers interest in this wood.
In addition, the application of a wood finish, particularly an oil finish, can cause the wood to become nearly black, and this allows it to be used as a substitute for the rarer and more expensive African, or Gaboon*, Ebony.
The grain of Wenge is straight. The texture is very coarse and there is little to no natural luster.
The endgrain of a Wenge board presents as diffuse and porous with large pores in no specific arrangement. Brown mineral deposits are occasionally present. The growth rings are distinct.
Wenge is very durable in terms of its resistance to fungal rot and it is also resistant to termite attack. These characteristics make is a favored utility wood in its native range although the commercial value of the wood when exported is generally to high to allow for these uses outside its native range.
Wenge is a lovely wood to look at, but honestly, it is frankly difficult to work with either hand or machine powered tools. While it can be worked and sawn, force is required. Cutting edges will blunt very quickly so frequent sharpening is essential to any measure of success. The use of stellite-tipped sawteeth and tungsten-carbide tipped cutting tools are recommended as alternatives that are likely to increase success when working with Wenge.
To further increase the joys of working with Wenge, bear in mind that it will sand unevenly due to differences in density between light and dark areas of the wood.
If you intend to nail or screw Wenge remember that it has a remarkable tendency to split, so pre-drill even the smallest of nail or screw holes.