C1070004 - Countersink Sets 90 Three Flute DIN - Three Flute Countersink 90, DIN 335 - Countersinking / Counter boring screw holes for Countersunk screws acc. to DIN 963, 964, 965, 966, 7513, 7516 - For Countersunk screws acc. to ISO 2009, 2010, 7046-1, 7046-2, 7047 - Chamfering of tapping holes - For use in machine applications. Type N - For non-ferrous, Type UNI - For difficult to machine materials Pieces 4 Range - 6.3, 10.4, 16.5, 20.5