Black Oxide Process

The Tru Temp low-temperature black oxide process is a blackening system designed for in-house parts finishing for manufacturers of iron and non-stainless steel components. Using a patent-pending two-step chemistry, the Tru Temp system produces a true black magnetite finish that is equal to regular black oxide in corrosion and wear resistance, but avoids the severe operating hazards and salt leaching problems commonly seen with black oxides, according to its manufacturer.

Unlike traditional black oxide processes that use a concentrated caustic soda solution (6-8 lb./gal) at very high temperatures (290°F) to blacken steel, the Tru Temp system uses mild solutions (about 1 lb./gal) at moderate temperatures (190°F) to do the blackening. The system's finish is a satin black magnetite, 1-micron thick with excellent resistant and corrosion to abrasion; it can withstand up to 300 hours salt spray.

Birchwood Casey Metal Finishes, 7900 Fuller Rd., Eden Prairie, MN 55344-9702. Tel: 952-937-7931. Fax: 952-937-7979.