What do you check in a mill certificate to certify a steel flange?

When certifying a steel flange using a mill certificate, you should check for the material grade and specification to ensure it meets project requirements. Additionally, verify the chemical composition to confirm it aligns with the specified standards. It's also important to review the mechanical properties, such as yield and tensile strength, as well as any relevant heat treatment information. Lastly, ensure that the certificate is properly signed and includes traceability information to the heat number.