Crimped wire with reinforced cup cover has perfect performance, good balance, high efficiency. The steel wire may have magnetism. With copper plating, it will avoid corrosion for a long time. Also, pay attention to storing in a suitable condition. When crimp cup brush used with water condition, please pay attention and avoid corrosion. Of course, if you don't want magnetism or easy corrosion, stainless steel wire is the ideal material.