According to ASTM A 967 Standard, passivation is “the removal of exogenous iron or iron compounds from the surface of a stainless steel by means of a chemical dissolution, most typically by a treatment with an acid solution that will remove the surface contamination but will not significantly affect the stainless steel itself.”
Jackson Tumble Finish uses the passivation process to provide the maximum elimination of all ferrous contamination, tooling particulates, and microscopic impurities on multiple varieties of stainless steel used in the market place. We use citric acid treatments to restore the stainless steel surface to its condition prior to machining. Jackson Tumble no longer uses nitric acid for passivation due to voluntary compliance with industry environmental concerns. Passivation prepares steel surfaces, making them very receptive to the next downstream operation. Passivation at Jackson Tumble Finish primarily involves stainless steel, but we handle other metals as well, including titanium.
Heavy, light, and a dry-to-touch options of organic and inorganic rust preventatives or inhibitors are available. Also available to this process is an extra step of SPIN DRY to remove excess rust preventative from parts with threads.