A Mill Certificate or Material Test Report is a document that confirms the chemistry, and physical properties of a material (Steel, bronze, etc.). This can be for a commercial material or against a specification (such as ASME for castings, pipes, tubes, nuts. and bolts, etc.), or against materials specifications such as ASTM’s. The report (Paper or Electronic media) typically contains the approval of the producer’s quality control personnel along with an any required approval stamp (as applicable).
When is a Mill Certificate required? Mill Certificates are required when traceability back to raw material is required, when evidence of conformance to a required chemical/physical material condition is required. It is also important when materials used are included in certified products (a Certificate of Compliance or Conformance is being issued).
During auditing of organizations, the main problem we have found associated with Mill Certificates is a failure of the receiving organization to check that the chemistry and physical properties (hardness, tensile strength, etc.) meets the specified requirements. It is important that either QC personnel receiving the Mill Certificate or Engineering support are educated on how to read and understand Mill Certificates.