Abstract: A device for joining metal strips passing successively into a strip processing plant includes two cutting punches having a respective cutting edge which is associated with a cutting edge of the respective other cutting punch. The cutting punches are movable along a cutting axis in a cutting motion to produce an undetachable join in an adjoining region by deformation. In the same position with respect to the cutting axis, the cutting edges of the cutting punches define a cutting gap which extends in the transverse direction and occupies a gap width in a width direction oriented at a right angle to the transverse direction and to the cutting axis. The cutting edges include an acute angle with the transverse direction, viewed from the cutting direction and in that the cutting punches are movable relative to one another in the transverse direction of the cutting gap to change the gap width.