The rounding-off of chaton claws when setting precious gemstones requires tools which are precisely adapted to the job on hand. Even when using tools with a perfect blade geometry, chips may build up and clog the cut. BUSH has developed the concave cutter {{411CCC}} ({{Clean Cut Cup bur}}) specially to prevent this. %% In addition to the specially developed blade geometry, it is the corss-recessed head that makes the 411CCC so special, for it improves the discharge of chips and increases the rate of removal - no clogging of the blades, resulting in a smoother surface on the workpiece. A circulating working method is a precondition for excellent working results. %% The 411CCC is made of tool steel and available per piece in 10 different sizes or as a complete set.