Superior Tool 18612 Stainless Steel Fitting Brush, 1/2" Will not rust-substantially out-performs standard fitting brushes Long lasting stainless steel bristles will not contaminate solder joints Superior Tool 18612 Half Inch Stainless Steel Fitting Brush (1/2") The ideal tool for cleaning standard copper plumbing fittings, aluminum and closed loop HVAC fittings Will not rust Double stem (4 wire) double spiral construction Spark proof