<p>Hot rolling is a critical process in steel production, where precise control of material dimensions and mechanical properties is essential. However, thermal expansion and contraction during reheating and cooling are often neglected in roll pass design, leading to inaccuracies in product dimension and increased rolling loads. In this study, the influence of the coefficient of thermal expansion (CTE) on the hot rolling behavior of steels was investigated by comparing a body-centered cubic plain carbon steel with a face-centered cubic TWIP steel. Experimental measurements, including high-temperature flow stress and thermal expansion characteristics, were conducted. Finite element simulations of rod rolling were then performed to analyze the effects of CTE on shape evolution, roll torque, and strain distribution. Results show that TWIP steel exhibits nearly twice the CTE of carbon steel (22.8 versus 12.1&#xa0;μm/m&#xa0;°C), resulting in larger billet expansion, increased reduction of area per pass, and higher roll torque (over 10% increase in the first pass). Furthermore, macroscopic shear bands were more pronounced in billets with thermal expansion considered, indicating significant strain localization. Thermal contraction during cooling also caused deviations from the target final product size, emphasizing the need for compensation in the final pass design. Based on these findings, a roll pass design strategy that accounts for both thermal expansion and contraction is proposed, particularly for high-CTE materials such as TWIP steels. This approach can enhance dimensional accuracy, reduce surface defects, and improve the overall quality of hot-rolled products.</p>