Electropolishing vs Passivation vs Anodizing vs Plating: How to Choose the Right Process

When to Use Electropolishing

Electropolishing is chosen when a customer expects their stainless steel parts to be "brighter". Often, customers ask for passivation when they actually desire the high-luster aesthetic of electropolishing.

 When Passivation is Enough

Passivation is the primary process for stainless steel when the goal is strictly functional—taking all the free iron out of the alloy to prevent rust without significantly changing the part's physical appearance.

When Anodizing is Required

Anodizing is specific to aluminum. It is used when a durable, often color-coded finish (like black anodize) is needed to meet strict aerospace or military specifications.

When Plating is the Best Option

Plating, such as zinc, is used to protect steel from rust. It is a versatile process that can include regular zinc, zinc with clear chromate, or zinc with yellow chromate.

How Rayco Helps Solve This

Rather than guessing, Rayco often recommends:

• Sending sample parts
• Running trial finishes
• Letting the customer physically evaluate the result



Because in many cases, seeing and holding the part removes all uncertainty.

Choosing the right finishing process isn’t just about checking a box—it’s about aligning material, performance, and expectations.



The best outcomes happen when that decision is made collaboratively, with a clear understanding of what the part needs to do—and how it needs to look.

Frequently Asked Questions