Abstract: A mandrel for the production of internally profiled, specially threaded tubes or cylinders (2) by the cold forging of tube shaped forging blank (2) around a profiled mandrel (3) by cold forging the workpiece (2) from its one end to the opposite end. The threaded mandrel is parted at or near its axial center and both halves (3a, 3b) are held together axially free under a given radial play. Both ends (8, 13) of the mandrel halves are shaped for the application of a spanner. The mandrel halves can be shaped slightly conical from the ends in towards the parting line, and the flanks of the mandrel threads (14, 15) can be ground so that the threads thicken slightly and continously from the parting line and outwardly towards the mandrel's ends. The thread depth in the mandrel can be slightly deeper than the required thread height on the cold forged tube or product.

Abstract: A mandrel for the production of internally threaded tubes or cylinders by the cold forging of a forging blank (3) around an externally threaded mandrel (2). The mandrel is formed with a conicity of 0.2-1.0% or preferably 0.4-0.7% and the flanks of the mandrel's threads can be ground so that the thread width is least at the mandrel's narrow end. The reduction of flank width can be 0.1-0.4% of preferably 0.2-0.3% for a length unit of the mandrel with the above named conicity. Preferably even the inner diameter of the mandrel's thread is made 0-0.5% less than the required inside diameter in the tube's or cylinder's thread.