This master thesis deals with the analysis of the influence quantity concerning the dimensional accuracy when shaping rods. When manufacturing/producing perfect-round bar steel it is possible that the adjustment of the rolling gap has to be examined again after the first dimensional check because influence quantities and their impact on the final dimensions are partly insufficiently known. This master thesis aims to show the influence quantity on the abutting block of specific parameter variations. Main influencing parameters, temperature, pace and roll adjustment are elicited by means of a Failure Mode and Effects Analysis (FMEA). Geometrical deviations due to the variations of influence quantities are shown and contrasted by use of simulations in DEFORM and test series in the rolling mill in order to draw conclusions for further attempts and changes of the production process.