Question

Stainless steel should probably be considered stain-less rather than stain-proof since it is not unusual to see some rusting on stainless steel. How could some of this rusting be prevented during fabrication?

Answer

Stainless steel can be contaminated with ferrous particles if fabricated using steel or iron tools (steel files or steel wool). These particles can embed themselves in the stainless steel and eventually start to rust. This rust can be removed by chemical washes.