Sizing Mill

According to the specification of tube, the range of diameter is from Φ30mm-Φ1000mm. Our sizing mill can cover the diameter range. The special sizing mill also can be designed by our expert team.

The framework is integrated casting component, in each one there are three rollers which are arranged evenly. After assembly, the caliber is manufactured simultaneously, so the caliber is high dimension precision. For the driving method of roller, the single and centralized drive all are practicable.

The sizing/stretch-reducing process plays an important role as the last deformation stage in the production of both seamless and welded steel tubes. As the last production stage, it is decisive in terms of the product variety and quality of the hot rolled tubes.

The diameter of the tube is reduced in a continuous pass - without inside tools in a variety of 3-roll stands - within the sizing mill and stretch-reducing mill. A smaller or larger number of stands is used depending on the diameter to be produced. During sizing, a low degree of longitudinal tension in the rolled stock is applied by using appropriate, fixed speed reduction from stand to stand  During stretch-reducing, on the other hand, the longitudinal tension and therefore stretching of the rolling stock is deliberately altered and the finished tube wall thickness thereby adjusted through variable speed adjustment.

By varying the stand management and speed settings, a broad spectrum of finished tube dimensions can be attained with just a few ingoing stock dimensions. Dimensional changes in the diameter and/or wall thickness of the tubes are carried out within short time intervals through stand changing and roll positioning. The flexibility of the process is used to minimize the machine and tool workload in the preliminary stage – the stretching process for seamless tubes and in the forming section for welded tubes. Besides the roll speed, calibration of the rolls and their development from stand to stand play a crucial role in terms of the quality of the outer and inner surface of the stretch-reduced tube.