Abstract: A pair of rollers receives the stock between them and are movable laterally in unison to advance the stock gripped between them in a feeding movement. A slide block is slidably carried by a disk and is provided with a coupling that is offset from the axis of the disk. The coupling is connected to the pair of rollers so that rotation of the disk will move them in their lateral movement. The length of the feeding movement is adjusted by moving the slide block relative to the disk to adjust the distance between the coupling and the axis of the disk. The slide block is provided with a measuring surface that is located so that the distance from the measuring surface to the reference surface corresponds to one-half the length of the feeding movement. The slide block is clamped in position by a locking plate that is slidably supported by the disk.