Now a day, cold working cannot reduce the thickness of work piece as well as the hot rolling for one time. The obviously cons is rolled metal in the solid matter had effect to be stress - strain. The metal grain is broken easily. And the investment for installation the large machine is too high. So that is the cause of production cost had increasing. Consequently, the propose of this research is to study the Permanent Deformation in forming process of hollow tube for Lead and Tin, by specify the thickness of the metal lead and tin with the thickness size as4, 3.5, 3, 2.5 and 2 mm. respectively. By means of roll the pipe with diameter 12 mm. and take it to test tensile and the results for lead and both types of metal tin have a tendency to the same way.
While the size reduces each occasion, the pressing strength always increased respectively. And the stresses will gradually decrease respectively. Refer to the result of this testing, the strength of rolling tin process will be weak as much as forming time processing. For the strain hard lead have more stress than tin, so it is appropriate for forming process.