1. What is material certification?
What exactly is material certification? Based on steel mill quality assurance practices, here is how to interpret the documentation: Name—Material Certification (often abbreviated as MTC or Mill Test Certificate; MTR/Material Test Report in North America; MTC or mill certificate internationally/in Europe; formally classified as “Inspection Documents” ranging from 2.1 to 3.2 under EN 10204; often referred to as CMTR/Certified Mill Test Report under ASTM and ASME standards);
Function—A foundational document linking a specific batch of physical material to its measured properties (proving that chemical composition and mechanical properties were actually measured rather than merely declared; without it, there is no verification that the material meets specifications); Requirements—Regardless of the specific name, the document must include the heat number, chemical composition, mechanical test results, and a declaration of conformity to material specifications (e.g., Clause 5 data); Types—EN 10204 Types 2.1 through 3.2, classified by the independence of the inspection (Type 3.1 is certified by the manufacturer’s independent inspection department; Type 3.2 is jointly certified by the manufacturer and a third party); Domestic Context—A quality certificate accompanies each delivery batch (e.g., Chapter 10 of the standard for recycled cast superalloy raw materials; specifies the grade; in my country, “quality certificate” is synonymous with “quality assurance certificate”). Summary of four key aspects: MTC and MTR refer to the same document; classification follows EN 10204 types; heat number, composition, and performance data are mandatory; and domestic quality assurance certificates are equivalent—these four points define the document’s nature.
2.
Content items
What should you look for in the content items?
Based on steel certification practices, the content should be reviewed as follows: Certificate Number—certificate number and date of issue (buyer’s order reference, heat number, coil/plate number); Product Description—grade, specification, form, dimensions, quantity, weight (product description, grade, dimensions, quantity, standard); Heat Number—heat/cast number (unique identifier for the steel, linking the certificate to the physical material; certificates lacking a heat number describe the grade but not the specific batch); Chemical Composition—ladle analysis and product analysis (elements such as C, Mn, P, S, Cr, Ni, Al, Si, Mg, Cu; e.g., for 304 stainless steel per ASTM A240: C ≤ 0.08%, Cr 18.0%–20.0%, Ni 8.0%–10.5%); Mechanical Properties—tensile strength, yield strength, elongation, hardness (plus Charpy impact test results and reduction of area, if required); Heat Treatment—heat treatment condition code (e.g., hot-rolled, normalized, quenched and tempered, solution annealed; furnace records required for alloy steel); Manufacturer—manufacturer name and address (original manufacturer, not the trader; includes steel mill information, origin, and testing date). In summary, there are seven key elements to check: certificate number, product description, heat number, chemical composition, mechanical properties, heat treatment, and manufacturer;
the document is valid only if all seven elements are present.
III. Procurement Requirements
What to look for in procurement requirements.
Based on material procurement practices, the following four aspects must be verified: **Order**—The purchase order must specify the EN 10204 certification type (e.g., EN 10204 Type 3.1, rather than a generic “material certificate”), applicable material specifications (e.g., ASTM A240 Type 304L or EN 10088-2 1.4307), and the scope of coverage (which specific batches or lots are covered by the certificate); **Grade**—The material certificate must clearly state the alloy grade and temper/condition as specified in the drawing (e.g., for 6061-T6 aluminum, verify three core items: grade/temper, chemical composition range, and mechanical property indicators; note that “T6” signifies peak strength achieved through solution heat treatment and artificial aging, whereas fraudulent certificates often list only “6061” without the temper designation); **Standard**—The governing standard (GB, ASTM, JIS, etc.) must be verified (composition ranges for the same grade can vary; for engineering orders, strictly ensure the standard matches—e.g., ASTM A36 structural steel, ASTM A479-304 stainless steel bar, or EN 10088-2 1.4401 European stainless steel); **Condition**—Material condition (e.g., hardness range of 28–32 HRC for solution-annealed material; for S22053 duplex stainless steel used in precision multi-axis fatigue specimens, the raw material quality certificate must comply with ASTM A182/A182M). **Item-by-item verification**—The grade field on a genuine certificate must explicitly state “6061-T6” (verify item-by-item against GB/T 3190 and GB/T 6892 standards during processing). In summary, procurement requires checking four key areas: EN 10204 certification type specified in the order, complete grade and temper details, matching standards (GB/ASTM/JIS), and clearly defined material conditions.
IV.
Machined Part Support
How to coordinate the supply of machined parts.
Based on machining quality practices, the documentation package is evaluated as follows: The “Three Certificates”—comprising three parts of the quality documentation for machined parts: inspection records (proving the part was actually measured rather than assumed correct by the machinist), material certification (traceable to the specific steel mill heat number and its chemical composition), and heat treatment certification (documenting the furnace process); Alloy Steel—material certification implies actual spectral analysis rather than a mere declaration that the bar stock is 4140 grade (traceability links the raw material to the specific mill heat number); Traceability—raw material certificates link heat numbers to specific machining batches (certificates correlate heat or batch numbers with purchase orders and finished batches; true traceability links the certificate to the material actually used in the part; this is especially critical for hard-to-source alloys like titanium); Coverage—material certificates provided by suppliers for each batch must include heat/batch numbers, actual spectral analysis of chemical composition, mechanical test results (tensile strength and hardness), and confirmation of specification compliance; Packaging—a complete set includes the material certificate, heat treatment certificate, and inspection records (stainless steel requires adherence to drawing specifications; plated or coated parts require an additional coating report)—machined parts require a four-part verification: inspection records, material certification, heat treatment certification, and a complete set of the “Three Certificates,” ensuring full traceability.
V.
Verification of Authenticity
What to look for during authenticity verification.
Based on practical experience in verifying steel quality certificates, here is how to validate authenticity: **Heat Number**—The heat/batch number serves as the steel’s “ID card” (the code sprayed on the coil or plate must match the quality certificate character-for-character; do not warehouse or process if they do not match; errors often arise from mixed stock, unmarked material during leveling/slitting, or loading the wrong material against the paperwork); **Cross-check**—First, verify that the certificate type matches the order (steel grade and certification standards, heat/casting numbers, chemical composition ranges, mechanical properties like yield and tensile strength, and dimensions/quantities; the more items cross-referenced against physical testing, the harder it is to forge the certificate); **Online Verification**—Baosteel electronic certificate verification (requires certificate number, contract number, material/label number, and verification code; older versions involve a ZIP file containing the PDF and a digital digest—the entire archive must be uploaded; newer versions allow three-step verification via the iBaosteel app by scanning the QR code on the digital or paper certificate); **Inspection**—Four-step verification for stainless steel certificates (Step 1: Check grade and condition; check the standard—GB, ASTM, or JIS—as composition ranges for the same grade may differ; check the heat and batch numbers, which are easily overlooked; Step 2: Check chemical composition—e.g., for 304 grade, look for 18–20% Chromium and 8–10.5% Nickel); **Declarations**—A trader’s declaration is not a material quality certificate (it is a seller’s assertion rather than a traceable record from the rolling mill and does not provide batch-level traceability).
**Summary of the four checks:** Character-by-character matching of sprayed heat numbers, item-by-item field verification, online scanning/verification (e.g., Baosteel), and distinguishing declarations from actual material certificates—these four steps clearly reveal authenticity.
Conclusion
Regarding how to provide material certification for automation components, the conclusion is to address five dimensions: documentation, content, procurement, supporting materials, and authenticity verification.
Documents—MTC/MTR (North American MTR, International/European MTC, EN 10204 inspection documents 2.1 through 3.2, ASTM/ASME-referenced CMTR, uniquely certifying measured composition and properties); Content—Certificate number and issue date, product description (grade, specification, dimensions, quantity), heat/cast number, chemical composition (Steel: C, Mn, P, S, Cr, Ni; Aluminum: Si, Mg, Cu), mechanical properties (tensile strength, yield strength, elongation, hardness, impact toughness), heat treatment conditions, manufacturer name and address; Procurement—Purchase orders must specify the EN 10204 type (e.g., 3.1), material specifications, and scope of coverage, with complete grade and temper designations (e.g., 6061-T6, where T6 indicates peak artificial aging), standards aligned with Chinese, US, or Japanese norms, and specific condition details (e.g., solution-annealed state, 28–32 HRC); Documentation Package—A complete set comprising inspection records, material certification, and heat treatment certification; actual spectral analysis for alloy steels; and traceability linking heat numbers, batch numbers, purchase orders, and production lots; Verification—Character-by-character verification of stenciled heat numbers (the “ID card” of the steel), item-by-item field verification (making forgery more difficult), online verification of Baosteel electronic quality certificates (using certificate number, contract number, verification code, or app scanning), and trader declarations (distinguishing them from official material certificates).
In summary, regarding industry practice for material certification: the mill MTC includes the heat number; the order clearly specifies the EN 10204 type; the three-part documentation package ensures traceability;
and the stenciled heat number is verified for authenticity—pass these four checks, and material quality concerns are resolved.
