The study investigates the impact of employing single-stage versus multistage mandrel cold-forming techniques to fabricate SS 304 U-shaped thin-walled metal bellows-type expansion joint profiles, with a specific focus on post-forming thickness variations and profile precision. The aim is to discern the thickness variations following the convolution profile formation in single-stage and multistage mandrel-forming procedures. The outcomes uncover noteworthy distinctions between the profiles produced using these forming methods, providing valuable insights for manufacturers.The study investigates the impact of employing single-stage versus multistage mandrel cold-forming techniques to fabricate SS 304 U-shaped thin-walled metal bellows-type expansion joint profiles, with a specific focus on post-forming thickness variations and profile precision. The aim is to discern the thickness variations following the convolution profile formation in single-stage and multistage mandrel-forming procedures. The outcomes uncover noteworthy distinctions between the profiles produced using these forming methods, providing valuable insights for manufacturers.