<p>This study investigates the influence of geometric parameters on the thermal performance of metal bellows through a detailed experimental heat transfer analysis. Metal bellows are flexible cylindrical components featuring periodic corrugations that enhance structural compliance and thermal interaction. Compared with straight tubes, the wavy geometry of bellows offers a larger effective surface area and promotes stronger fluid mixing, resulting in enhanced heat transfer characteristics. Due to the complex flow behavior encouraged by the corrugated geometry, analytical prediction of the heat transfer coefficient is difficult. Therefore, experimental approaches are adopted to evaluate the thermal behavior of metal bellows and to develop empirical correlations. The present work examines heat transfer in both radial and axial directions by systematically varying key geometric parameters, including convolution height, convolution number, and outer diameter. The experimentally obtained results are compared with the existing standard equation and are also used to establish new empirical relationships. Furthermore, the metal bellows’ thermal performance is assessed under standard operating conditions by analyzing the effects of geometric variations across a range of flow velocities and heat inputs. Experiments are conducted at 1, 2, and 3&#xa0;m/s of flow velocities with 50, 100, 150, and 200 Watts of heat inputs. Thermal performance is evaluated using parameters- heat transfer coefficient, Nusselt number, and Reynolds number. The findings provide valuable insights into the role of geometric configuration in augmenting the heat transfer efficiency of metal bellows for thermal engineering applications.</p> Graphical Abstract <p></p>