A floorboard and an openable locking system therefor comprise an undercut groove on one long side of the floorboard and a projecting tongue on the opposite long side of the floorboard. An array of receiving apertures is arranged in the flux frame. The second cutting device 430 also includes a cutter wheel 412 for forming scribing lines on the second substrate and a breaking roller 416 which let the scribing lines penetrate through the thickness direction of the second substrate.