A mill test certificate is the document that ties the steel in your container to the heat it was rolled from, and it is the only paper trail that survives after a coil has been cut, slit or shipped. It is issued by the producing mill rather than by the trader, so it carries the mill letterhead, a certificate number and a heat or cast number. That same heat number appears on the coil tag and on the packing list, and if the three references do not agree, the certificate does not describe the material you are holding.
The certificate usually reports two blocks that matter. The chemical block gives ladle analysis for carbon, manganese, silicon, sulphur, phosphorus and any alloying additions, measured against the limits of the standard the order was placed to, so you can see whether the heat was made comfortably inside the specification or at the edge of it. The mechanical block gives yield strength, tensile strength and elongation from test pieces, together with the heat treatment condition, because the same chemistry in a normalized and an as-rolled condition does not deliver the same properties in service.
Two checks catch most of the problems. First, confirm that the standard printed on the certificate is the standard on your purchase order, since a supplier quoting an equivalent grade is not always guaranteeing the property you were relying on. Second, check that the certificate covers the quantity and the dimensions actually shipped, and ask for a copy before loading rather than with the documents, so that a discrepancy can still be resolved while the material is at the mill.
Xi’an Junlin Chicheng Metal Products Co., Ltd has supplied steel since 2003, first through our predecessor business and now under this company, sourcing from long-term partner mills that operate ISO 9001 quality systems. Every order we ship carries a mill test certificate traced to its heat number, and we will tell you which documents the mill issues for the grade you ask for. Send the grade, the standard, the size and the destination port, and we will confirm what the mill can hold, the lead time and the shipping weight, usually within one working day.