摘要 |
A pasty mass to form a welding electrode is formed in a slubber comprising at least two intermeshing rotatable endless screws enclosed in a common casing. The exterior surface of the screw threads has a layer of partic. hard, metal applied along its length. Specif. the welded layers forms a flange which extends only along the exterior part of the thread, and on the outward facing part of the particular screw. |