It is difficult to determine which material is better without specific information about the usage requirements and application. However, S235J0 and DX51 are both commonly used in different industries.
S235J0 is a non-alloy structural steel with a minimum yield strength of 235 MPa. It is mainly used in construction, machinery manufacturing, and civil engineering projects.
DX51 is a galvanized steel with a zinc coating, which offers increased corrosion resistance. It is commonly used in the automotive industry, electrical appliances, and construction materials.
The choice between S235J0 and DX51 will depend on factors such as the required mechanical properties, corrosion resistance, and specific application requirements in different industries. It is important to consult with material experts or engineers to determine which material is more suitable for a particular project or application.