Flour milling is defined mainly with grinding process. Grinding is the process in which wheat kernel is separated from the husk and the germ and the endosperm is transformed into particles. Wheat passes through many operations until this grinding stage but rolls realized the grinding process which is the basis of milling. Grinding process in the mills is defined as the separation of kernel from husk and germ by passing through different stages. The most important element in this stage is the rolls that realize the grinding process. Each parameter related with the rolls is significantly effective on quality, yield, tonnage and energy usage. Therefore, selection of the right rolls and making proper adjustments related with the rolls is significantly important. Thus, we tried to find the answers for the mostly wondered about the rolls on this issue. Experts states on the subject that there are some universal consent rules based on the long experiences about the features of the rolls and their adjustments during practice but the real important thing is experience as there are too many elements affecting the process.