When a die punches a piece from a strip of steel it leaves a sharp burr on the edge. Burrs are removed by putting the pieces into a tumbler filled with ceramic pellets and a slurry of grit and water. The tumbler vibrates violently, churning the contents together and wearing the burrs off and putting a polish onto the pieces. Click here for the rest of the story:http://tinyurl.com/leatherman-tour