Abstract: An apparatus for restoring the surfaces surrounding blind or through bores of metallic workpieces has a housing for an axially movable shaft which can be placed into axial alignment with the bore of a workpiece, a spindle which is rotatable in and is movable axially with the shaft, and several tool carriers each of which can be removably connected with the front end portion of the spindle. At least one of the carriers supports a welding nozzle which is surrounded by a nozzle for discharge of a protective gas and can be used to deposit fillets of molten welding wire along the surface or surfaces surrounding the bore. Another carrier supports a material removing tool which is used to remove the surplus of the fillet, and a third carrier is used when the restored surface is to be provided with a thread. The third carrier supports a thread cutting tool.

Abstract: To repair worn-out bearing lugs of iron bolt bearings, excess material is applied to the bearing surface by means of a welding head rotating inside the bearing lug. This material then is turned down to the regular bearing surface.