Four-roller type sizing mill apparatus for producing round steel rods

摘要

A four-roller type sizing mill apparatus for forming round steel rods, comprises two four-roller mills each having two pair of facing rollers. One pair of facing rollers is arranged in rolling direction perpendicular to the rolling direction of the other pair of rollers. The two four-roller mills are arranged in line, with the rolling direction of one of the two four-roller mills being shifted by 45 DEG from the rolling direction of the other four-roller mill. The two pair of rollers of a first four-roller mill positioned closer to the rolling material inlet are separated from each other by a distance which is greater than zero and not greater than five times the projected contact length of one of the pair of rollers positioned closer to the rolling material inlet. The distance is measured between a first standard straight line which passes through the centers of one of the pair of rollers and lies on a plane parallel to the side surfaces of the same pair of rollers and a second standard straight line obtained by projecting the axes of the other pair of rollers onto the above-mentioned plane.