A clear purchase order prevents most quality disputes. Use this 10-point checklist:

1) Grade and standard: e.g. "316L per ASTM A240" or "1.4404 per EN 10088-2". Avoid grade names alone. 2) Product form and process: hot rolled / cold rolled, coil / cut sheet, seamless / welded tube, etc. 3) Dimensions and tolerances: thickness, width, length, ID/OD, coil weight; state the dimensional standard (A480, EN 10131...) and tolerance class. 4) Surface finish: 2B, BA, No.4, No.8, with grain direction if relevant; approved sample for appearance parts. 5) Delivery condition: annealed/pickled, skin passed, cold-worked temper, edge condition (mill edge / slit edge). 6) Mechanical/chemical extras: additional requirements beyond the standard (e.g. Ni min, PREN min, impact tests). 7) Testing and inspection: hydrostatic, eddy current, UT, IGC; sampling and witness points. 8) Certification: EN 10204 3.1 or 3.2; heat number traceability. 9) Packaging and marking: protection film, interleaving paper, moisture protection, marks and labels. 10) Commercial terms: Incoterms, delivery date, documents, claims period and retest rules.

Tips:

• For dual-certified material, require both standards on the certificate. • For critical parts, agree PMI and third-party inspection. • Keep a signed technical annex; verbal agreements do not survive a claim.

The PO is a technical document as much as a commercial one — write it that way.