The surface finish of the outer diameter of the embryo tube scraped by hand is barely acceptable. If the embryo tube is too thick, it is difficult to meet the requirements of the rolling mill. Because the outer embryo layer of the tube is too thick and the embryo spot is too deep, it can only be processed by heavy equipment. At the beginning, only one or two pieces can be scraped. After that, the working efficiency has been greatly improved in our company's practical production. The development of six, eight pieces and large diameter skin scrapers is basically in line with the process of the rolling mill requirement.