The Lumiclad aluminum blackening process from Birchwood Technologies produces a rich black finish on aluminum components and is recommended for power transmission components such as couplings, electrical card cages, and military and weapon components.Lumiclad is also electrically conductive and provides predictable chassis grounding in desired products. It forms a nearly non-dimensional black oxide finish on all aluminum surfaces. It is reportedly very durable, clean and tightly adherent to the metal substrate. The Lumiclad process produces a uniform coating thickness of .000060 in. (1.5 micron) that will not close down hole diameters or change critical part dimensions. The smooth black finish has a slightly porous crystal structure that absorbs an optional topcoat such as a dry-to-touch sealant, light oil, or clear polymer. By using a conventional immersion seven-tank process line, the process is easy and safe to operate so that manufacturers can operate it in-house. The short process cycle takes just 30 minutes. This process can be utilized for jobs of any size component, large or small, and for large quantities of smaller parts. Parts can be finished on racks as well as in baskets or barrels without the need to individually clamp each part, and the process is electroless so no individual racking is necessary.