The control of product shape and dimensions poses some problems in hot ring rolling. In the rolling process, material flows both circumferentially and axially, which leads to increased ring height. Changes in shape and dimensions of ring cross section depend on several process parameters, which makes it difficult to predict ring diameter. This paper presents the results of a study investigating the hot radial rolling process for C45 steel rings in terms of the effect of main roll feed speed on product geometry. It was found that the application of a higher feed speed of the main roll and thus of a greater ratio between this speed and circumferential speed of the main roll led to increased axial material flow and reduced cross-sectional defect known as ”fishtail”. Machining losses generated due to cross-sectional defects were also determined. Results were used to determine the feed speed to circumferential speed ratio ensuring the lowest possible cross-sectional defect and material consumption.