To the orienting professor of the TCC Professor Rubens Barreto Lighter for the orientation and aid in the elaboration of this work. 1 SUMMARY the work in question deals with the quality control in the manufacture and welding of metallic steel structures carbon saw process of welding MIG/MAG. Explained of simple form the process of welding MIG/MAG and its main defects/discontinuities, as well as, of detailed form its causes solutions. One prices and presented of the percentages of defects/discontinuities found before and after the implementation of the quality control. To the end we concluimos the importance of this tool of management for the elaboration of the action plan to diminish or to eliminate these defects. As first justification has it requirement of presentation of a work of conclusion of course (TCC) for the attainment of the heading of Technician in Mechanics for the School State Technique Philadelpho G. Netto de Sao Jose of the Black River. SP. After that the necessity of integration of the diverse ones exists disciplines and concepts learned during the related course, amongst them: Technology of Projects, Technology of Automation, Technology of Manufacture, Technology of Elements of You scheme, Technology Mechanics, Eletroeletronica, Digital Representation of Components of Mechanics, Graphical Representation and Components of Mechanics, Applicatory Informatizados in Mechanics, Language, Work and Technology, Industrial Technology, Technology of CNC, Ethics, Citizenship and Ambient Management. The project is also justified for the search of productivity increase, guarantee of the quality and of the competitiveness for the diverse organizations gifts in the industrial park.