Below is a list of Stainless Steel Expanded Metal manufacturers from Trafford, Pennsylvania. Stainless steel expanded metal is a highly anti-corrosive sheet, mesh or grate of solid construction resulting from the simultaneous incising and stretching of metal plate or sheet. Though referred to singularly, stainless steel is actually the name of a group of metals rather than a specific alloy of steel. Like expanded steel, these alloys are extremely durable and have a very high weight to strength threshold making them popular in a number of industrial applications.