Rotary cutting tool assembly

A rotary cutting tool assembly comprising a toolholder comprising a central tool holding receptacle and a cutting tool comprising a holding projection that can be detachably held in the tool holding receptacle and via which the cutting tool is secured to and radially centered on the toolholder, wherein the holding projection has at its free end a pin-like, first centering section and an adjoining externally threaded section, wherein the holding projection ends in a radially outwardly projecting shoulder having an end face abutment surface, and the tool holding receptacle has an internally threaded section for receiving the externally threaded section and a first centering seat section which is positioned deeper in the tool holding receptacle and in which the centering section of the cutting tool is received,

• characterized in that the axial length (L) of the first centering section is greater than the axial distance (I) from the start of the internally threaded section to the start of the first centering seat section.