Rolling method is the most efficiency and lowest noisy method among the typical tube reducing methods. SG-8A and SG-12A rolling mills are such a machine that reduces the diameter of the tubular element by 8 or 12 pairs of rolls. After the filling process the tubular elements are inserted into the rolls box of the machine, it in turn passes through each pairs of the rolls with diameter reducing, round correction and straightening and then extracted by the extractor.
　　It needs only exchanging the rolls or the rolls box, so that we may make the heating elements in different diameters and different values of the diameter reducing.
　　SG-8A and SG-12A are the remodeled machines. It saves 32% of the electric power, raises 4% of processing speed and reduces 8dB of the noise in comparison with the old model. It has a better protection for the machine. The working life of this machine has been improved than the old model.