FE 550D TMT bars represent a higher grade compared to FE 500D, indicating superior mechanical properties. While FE 500D bars have a minimum yield strength of 500 MPa, FE 550D bars boast a higher minimum yield strength of 550 MPa. This makes FE 550D bars stronger and more resilient against heavy loads and seismic forces. Both grades undergo similar thermo-mechanical treatment processes... https://bit.ly/3KV51a1