This study aims to find what is only a. The influence on the rublas is in the process of  engineering grap with the material of ST 42 and to find the parameters of what results in the complexity of a product and a process that strong against the ilingvating, develop quality. Products that strong components of components and minimize ariate are ariate around the target. From the test results in order to know the relationship, shism, feeding and cooling variations against the loss of the surface studies have shown. (1) is not a significant parameters vang of rudeness in the surface of the steel material of ST 42 (2) vang parameters resulting in the surface of the most well known steel material of ST. The matal as JCK with a 0.115 and subtlety 3.42 µm.