If your work-piece is either brass or copper, then brass wire is the most suitable choice. Brass wire (as well as bronze wire) will not generate sparks when struck against other metallic surfaces, and is suitable for hazardous environments (1) .
Description
Specification
Brass bristle brushes are used on softer surfaces or when it is necessary to clean a harder surface without marring it. Brass bristle brushes are also used in potentially flammable environments where non-sparking tools are required.