I bought these because I weld aluminum. Anyone involved in welding knows that you need a special stainless steel brush to clean aluminum before welding. Well I bought them when I bought my new TIG welder. and it took me a while to figure out why my welds were suddenly turning crap. At first I thought it was the welder but then I checked the brushes with a magnet and made sure they are NOT stainless steel. They soiled my welds. The brushes are welded so I gave them 3 stars for what they are. But the fact that they were listed as rust free is false advertising.