摘要 |
Disclosed herein is a method for manufacturing a screw comprising a continuous thread with a variable thread pitch, in which method a blank is rolled between two rolling dies, wherein in each rolling die a rolling profile is formed that comprises a host of curved non-parallel depressions. The depressions are designed and arranged in such a manner that during rolling no volume transport, or as little volume transport as possible, in the axial direction takes place, or a volume transport from a region of the blank where a thread section with a larger thread pitch is to be formed, to a region in which a thread section with a smaller thread pitch is to be formed takes place. |