Passivation is the chemical process that, when done correctly, improves stainless steel's resistance to stains. In other words: Passivation makes stainless steel more stainless. Once a piece of steel is passivated, it's more stainless than ever – but is not stain-proof.

The passivation process involves removing microscopic iron particles that have been deposited during any manufacturing steps. We also reduce the iron at the surface of the stainless steel. Removing the iron makes the chromium react with oxygen, which forms an invisible, protective layer. This reduces the likelihood of that steel ever becoming stained or rusted in the future.

Stainless steel passivation is a preventative measure. In general, it does not remove existing stains or rust spots; other methods are needed to do that, including light abrasion, bead blasting, tumbling and sanding. Passivation will also not remove weld scale, black oxides or burn marks from welding. Those must be removed by pickling, a process often done in conjunction with passivation. Pickling is normally performed before passivating.

To be classified as "stainless," steel must have a chromium content exceeding 10.5 percent. The chromium helps the steel's iron portion resist combining with oxygen, which is how rust is generates. Steel can stain or rust, but does so much less than other alloys.

Why Invest in Stainless Steel Passivation?

Passivating your stainless steel will increase your metal's resistance and provide a better, more aesthetically pleasing product for your customers. Since stainless steel is expensive, passivation is well worth the investment.

At RP Abrasives, we use citric acid to passivate steel, which is the most effective, eco-friendly and safe process. Not only does citric acid provide a superior barrier to the surface of steel, the chemical's easy to dispose of when used up because it is not hazardous waste. We also passivate using reverse osmosis, deionized water, which assures that the steel is ultra-clean when we're done with it.

Ask Us About Our Stainless Steel Passivation Services!

For a no-obligation consultation, call us today at (603) 335-2132 or email This e-mail address is being protected from spambots. You need JavaScript enabled to view it . We're based in New Hampshire, but we offer services to customers throughout Massachusetts, Maine, Vermont, Connecticut, Rhode Island, New York and nationally.