Surface Passivation

– Onsite and  fully qualified

Our ESMA ultrasonic aqueous cleaning unit is designed and built specifically to ultrasonically clean and passivate medical devices. Our ultrasonic cleaning unit can handle all metals types including polished aluminum, zinc, stainless steel, copper, brass, and other ferrous metals. ESMA ultrasonic cleaners are compatible with cGMP and the addition of the passivation service has allowed us to offer our medical device customers a comprehensive fully validated manufacturing service which supplies cleaned and passive parts .

What is passivation and when is it needed?

Passivation is a process that creates a protective layer on the outside of metal products to ensure they aren’t vulnerable to the elements that surround them, such as air and water.  Acid passivation involves exposing a clean piece of metal to nitric or citric acid, which exposes a part’s chromium to the oxygen in the air. The chromium reacts with the oxygen to create chromium oxide, a protective layer that’s just a few molecules thick but that protects the underlying metal from becoming damaged. Passivation simply creates the protective surface layer.

Passivating stainless steel is typically accomplished in industry by dipping the part in a bath of nitric acid. Nitric acid dissolves any free iron or other contaminants from the surface, which cleans the metal, and it re-oxidizes the chromium. This process takes about 20 minutes.

Our passivation unit has separate alkaline and acid tanks each with its own filtration systems, and two rinse tanks. We can our protect cleaning and passivation programs so that strict control is kept over which programs are run. We have successfully integrated the passivation service into validated production processes for components manufactured for our Medical Devices customers.


Phone Us


Mail Us

Call or mail our team of experts!

Smithstown Engineering, photographed by Keewi Photography