Multiple knife blocks for use on plain shafts or expanding air shafts. They are available with or without individual fixing, cutting on one or on both sides, and of course in all current steel qualities. What is more, multiple knife blocks are available in two-piece design, type DUO RING. This patented solution by Dienes allows to change the tool without having to disassemble the shaft and thus grants setup time savings of several hours per tool change!