Abstract: In a rolling mill plant for the manufacture of seamless tubes, a piercing mill (2), a planetary skew rolling mill (15) and a sizing or stretch-reducing rolling mill (18) are arranged one after the other. In order to improve the output and the quality of the products of plant of this kind, it is proposed not to withdraw the shaft rods (11) used during the piercing operation in the mill (2), but also to use them as internal tools in the planetary skew rolling mill (15). The shaft rods can then remain at the entry end upstream of the planetary skew rolling mill (15) from where they can be returned to the piercing mill (2). Alternatively (FIGS. 2 and 4) they can also pass through the planetary skew rolling mill and be returned from the delivery end thereof to the piercing mill. The insertion, hitherto required, of rods into the hollow ingots before entering the planetary skew rolling mill is not required. The heavy scaling of the surface of the bore in the hollow ingot thereby occurring is avoided.

Abstract: A rolling mill plant has a planetary skew rolling mill and a reducing or sizing rolling line disposed at a short distance therebeyond for the purpose of manufacturing tubes. In order to avoid axial stressing of the work material between the planetary skew rolling mill and the reducing or sizing rolling line when the work material is simultaneously located in both of them, a tension and compression measuring device is disposed in the region of the reducing or sizing rolling line for the purpose of corresponding regulation of the latter's drive motor. A torque measuring device is disposed between the mounting of the mandrel rod of the planetary skew rolling mill in order to be able to detect torque stresses in the work material which are then eliminated in dependence upon the measured values of the torque measuring device by corresponding regulation of the rotational speed of the rolls and of the rotor of the planetary skew rolling mill.

Abstract: A push bench is provided for the production of tube blooms in which the last roll stands of a plurality of roll stands one behind the other in the direction of pushing have radially adjustably supported rolls, said radially adjustably supported rolls being radially adjustable at the beginning of each working cycle with regard to the diameter or diameter tolerance of the mandrel rod being used for that work cycle.

Abstract: The rollers of a push bench for the production of tubular blooms are axially displaceably journalled on respective spindles so that the rollers are centered by the bloom. For machining the working surfaces of the rollers, the rollers, or their shafts to which they are fixed, can be axially locked in position and the roller shaft has a releasable coupling for coupling the roller shaft to a drive motor or drive shaft, whereby all the rollers can be machined simultaneously without removing them from the stand.

Abstract: A tube push bench is provided having an elongated guide bed, a toothed rack mounted in the guide bed for longitudinal displacement thereon, a mandrel rod at one end of said toothed rack driven thereby for longitudinal displacement with said rack for moving a tubular bloom, at least three drive pinions engaging said toothed rack in close packed succession and drive means driving said pinions.