Tru Temp

May 01, 2010

Tooling designers can achieve a durable, protective finish with the new TRU TEMP low temp black oxide process from Birchwood Casey. The process is a proven advancement for protecting high value tooling and fixtures used in all types of manufacturing, especially vehicles, subassemblies, power transmission components and other machinery. In storage, shipment and startup, the black oxide finish serves as a protective barrier against corrosion and provides break-in lubricity and anti-galling protection. The finish complies with MIL-DTL-13924, Class 1 and withstands 100 to 300 hours of salt spray. Ideal for automotive fixtures including toolholding, workholding, welding, fastening, gaging and associated equipment, the TRU TEMP process forms a nondimensional, deep black finish with long-term corrosion resistance, according to the company. It is ideal for components manufactured to tight tolerances, yet doesn't affect function. Because of its crystalline structure, the finish has inherent break-in lubricity and galling resistance, thereby serving as a direct replacement for zinc-phosphate finishes, but without the hazardous zinc content. This property makes it possible to operate the TRU TEMP process without the need for hazardous waste treatment equipment. The process itself operates at low temperature and contains no pollutants. Total process time is 25 minutes, and operating cost (including chemical and heating cost) is just 2 to 3 cents per pound of finished work. Most existing tank lines can be retrofitted for TRU TEMP at low cost. New automated and manually operated process lines are also available direct from Birchwood Casey in all sizes. A major benefit of the TRU TEMP process is that it operates at 200°F, eliminating the severe splattering and boilover hazards often experienced with conventional hot (290°F) black oxide finishing. Also, TRU TEMP's mild solutions prevent red coatings and white salt leaching that often plague ordinary black oxide finishes. The TRU TEMP process contains no metals or other pollutants, so no waste treatment is required. Rinse waters are normally sewerable as nonhazardous discharge. This benefit simplifies the installation and minimizes the capital investment for setting up the process line.

Related Glossary Terms

  • black oxide

    black oxide

    Black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.

  • corrosion resistance

    corrosion resistance

    Ability of an alloy or material to withstand rust and corrosion. These are properties fostered by nickel and chromium in alloys such as stainless steel.

  • galling


    Condition whereby excessive friction between high spots results in localized welding with subsequent spalling and further roughening of the rubbing surface(s) of one or both of two mating parts.

  • lubricity


    Measure of the relative efficiency with which a cutting fluid or lubricant reduces friction between surfaces.