Rules Clarification: Costume vs. Professional armor

Quick question:

I am making my own chainmail. I am using galvanized steel wire. Does the galvanization of the steel disqualify it from being professional grade (assuming it meets all other standards). I am simply curious as to how strict we're going to be on the "authentic materials" stipulation. I ask this only for the sake of clarification. I don't have a stance either way, I just want to understand the rules as best I can.

Steel is steel, so it's Professional grade.  Stainless steel has been graded as professional, so galvanized counts.

Thank you very much! I was curious, so I decided to ask.