Grinding and/or erosion machine (10) for machining a chip-cutting rotary tool including a tool body (18) and several cutting plates (19) per existing pitch (TR). A control device (25) activates an axis arrangement (11) to move a machine tool (12) and the rotary tool (13) to be machined relative to each other. An interface device (26) triggers a data import function for reading-in the position data of the cutting plates (19). The position data (P) describe at least one angular value (α1, α2), a first length value (z1) and a second length value (z2). The control device (25) imports the position data (P) in chaotic order and allocates the position data (P) of each cutting plate (19) in the imported machine data set (M) to respectively one separate virtual pitch (TV), independent of whether the cutting plates (19) belong to a common pitch of the rotary tool (13).