Dixie Gunsmithing
Moderator Emeritus
Carding uses a carding wheel, which has very fine steel bristles on it, (0.0025" to 0.003" dia. wire). much softer than a standard wire wheel. It serves the same function as steel wool, just that it's faster. Below is a link to the wheels.
http://www.brownells.com/gunsmith-tools-supplies/metal-prep-coloring/wire-brushing-carding-tools/0025-stainless-steel-brushing-wheels-prod6762.aspx
http://www.brownells.com/gunsmith-tools-supplies/metal-prep-coloring/wire-brushing-carding-tools/0025-stainless-steel-brushing-wheels-prod6762.aspx