The present invention relates to a workpiece carrier for transporting and/or storing components of a drug delivery device, comprising: an array of accommodating recesses extending in a first lateral plane (x, y) and being adapted to receive at least one component of the drug delivery device, at least one stack forming structure adapted to mate with a corresponding stack forming structure of another workpiece carrier for mutually aligning workpiece carriers when stacked on one another, wherein the center of the at least one stack forming structure is arranged laterally offset with respect to the center of the array of accommodating recesses in at least one lateral direction, and wherein the stack forming structure comprises a surrounding edge comprising at least in sections a corrugated or undulated structure.