A leader in the metal finishing industry since 1928, Keystone Corporation provides high quality Passivation services for stainless steel. Our lines are built to handle both large and small work pieces, with lifting capacity up to three tons.



Stainless steel is an inherently corrosion resistant material. However, when stainless steel is machined, formed or fabricated, free iron can be introduced to the surface that can corrode independent of the base material.  Proper Passivation of stainless steel with an oxidizing acid such as nitric acid removes this free iron and promotes the growth of a thin, dense protective oxide layer which maximizes the corrosion resistance of the stainless steel.

It is important to note that stainless steel is corrosion resistant but not corrosion proof.  The degree of corrosion resistance of a stainless steel alloy is a function of the alloying composition, heat treatment, internal stresses and passivation treatment. Selection of the correct passivation process is determined by the stainless steel alloy involved and by the specification requirements. Our Engineering team can assist with selection of the passivation process that is best suited for your requirements.  



Keystone Corporation Passivation meets the following specifications:

  • AMS-QQ-P-35 - Types I-VI
  • AMS 2700 - Method 1 Nitric Passivation Type 1-6
  • ASTM A967
  • ASTM A380
  • ISO 16048
  • Commercial and customer generated specifications



For more than 90 years, Keystone Corporation has assisted customers in completing commercial orders ranging from a few specialized pieces to high volume applications. All finishes are available for both Rack and Barrel applications. We maintain superior quality control through the entire finishing process, ensuring top quality Passivation at an affordable cost for any project.  Contact Keystone today to receive a personalized quotation based on your specific requirements.

Plated metal parts

Request a Quote

Please fill out the short form below to get started today. A member of our team will contact you shortly to discuss your needs.