Cassette mounted roller guide box is a moving platform is supported and guided by a set of rollers. The platform is coupled to a cassette that contains the rollers. The platform is kept from swaying or deviating from its intended path by the roller guide box, which also serves to keep it travelling in a straight line. By decreasing friction on the milled steel to a minimum, cassette mounted roller guide box increases yield rate and quality while preventing seizure and abrasion marks. In a continuous rolling operation, where the stock being rolled is appropriately twisted between each pair of adjacent rolling mills, it is largely used.