An apparatus for cutting sheet metal discs (31) from and welding sheet metal discs (31), or other smooth-contoured sheet metal pieces, to a sheet metal strip (20) or other workpiece, particularly an endless sheet metal strip, e.g., in a double-strip press. The apparatus has guide for securing a cutting apparatus (34), welding apparatus, and a machining apparatus. The guide can be positioned on or against the sheet metal workpiece (20). The apparatus has a backing (32) positioned to support the disc about a weld seam to be produced. The guide (8) are held against the sheet metal strip by at least one electromagnet (2), preferably a plurality of electromagnets (2), and/or at least one vacuum element (35a, 35b, 35b, 35c), preferably a plurality of vacuum elements. Holding elements ( 12, 13, 14) are provided to secure the cutting and/or welding apparatuses (34, 34), which are moveable along the guide (8) by action of a motor (3).