| Material Grade | 304 or 304L austenitic stainless steel plate | Products should conform to the applicable requirements of ASTM A240, EN 10088-2, JIS G4304, or an equivalent recognized standard. | Material test certificate, heat number, chemical composition report, and applicable standard designation. | Critical |
| Chemical Composition | Chromium, nickel, carbon, manganese, silicon, phosphorus, and sulfur content | Typical 304 chemistry includes approximately 18% chromium and 8% nickel; exact limits must follow the selected standard and product specification. 304L requires a lower carbon limit than standard 304. | Heat-specific laboratory analysis, preferably verified by an independent or accredited laboratory. | Critical |
| Mechanical Properties | Yield strength, tensile strength, elongation, and hardness | Values must meet the selected standard, delivery condition, thickness range, and applicable product specification. A single generic value should not be accepted for every thickness. | Certified tensile-test results, hardness records, test direction, and sample location. | Critical |
| Dimensional Accuracy | Thickness, width, length, flatness, squareness, and edge condition | Dimensional tolerances should be stated against ASTM, EN, JIS, or an agreed purchasing specification. Thickness tolerance may vary according to nominal thickness and rolling method. | Inspection plan, calibrated measurement records, tolerance chart, and sample inspection report. | High |
| Surface Finish | 2B, BA, No. 1, No. 4, HL, or custom finish | Finish terminology should be linked to a recognized standard. 2B is commonly cold-rolled, heat-treated, pickled, and skin-passed; BA is produced using a bright-annealing process. | Surface-finish specification, representative samples, roughness readings where required, and inspection criteria. | High |
| Production Route | Melting, continuous casting or ingot casting, hot rolling, annealing, pickling, cold rolling, and finishing | A controlled process route with traceability between each major operation is preferable. The route should match the required thickness, finish, and mechanical properties. | Process flow chart, equipment list, heat-treatment records, and production traceability procedure. | Critical |
| Rolling Technology | Hot-rolling and cold-rolling capability | Manufacturers should demonstrate stable thickness control, crown and flatness control, roll maintenance, and appropriate reduction schedules for the ordered gauge. | Mill capability statement, thickness-control records, flatness data, and recent production samples. | High |
| Heat Treatment | Solution annealing and cooling control | Heat treatment should be controlled to achieve the specified metallurgical condition while minimizing distortion, scaling, and surface defects. | Furnace calibration records, temperature curves, cooling procedure, and heat-treatment certificate. | High |
| Surface Defect Control | Inspection for scratches, pits, roll marks, edge cracks, scale, inclusions, and laminations | Inspection criteria should be defined before production. Critical applications may require additional non-destructive testing or enhanced visual inspection. | Quality-control plan, defect classification standard, inspection photographs, and non-conformance records. | High |
| Testing Capability | Chemical, tensile, hardness, corrosion-related, dimensional, and surface testing | Testing equipment should be calibrated and operated under documented procedures. Testing frequency should be defined by the standard, contract, and risk level. | Calibration certificates, laboratory scope, test methods, and sample test reports. | Critical |
| Quality Management | Documented quality system and corrective-action process | An ISO 9001-certified quality management system is a useful baseline, but certification should be verified and supported by actual process controls. | Valid certificate, certification scope, audit summary, inspection plan, and corrective-action records. | High |
| Production Capacity | Monthly or annual plate output for the required grade, thickness, width, and finish | Capacity should be stated as available capacity for the specific product range, not only the total output of a larger steel group or facility. | Capacity statement, production schedule, equipment bottleneck analysis, and references for comparable orders. | High |
| Maximum Product Range | Available thickness, width, length, and finish combinations | The supplier should confirm the normal production range and the maximum range available through internal processing or qualified partner facilities. | Product catalogue, mill capability table, sample dimensional certificate, and outsourcing disclosure. | High |
| Heat and Coil Traceability | Traceability from raw material to finished plate and shipping documents | Every plate, bundle, or production lot should be linked to a heat number and corresponding test certificate without gaps in the record. | Traceability sample, bundle marking photograph, packing list, and matching material certificate. | Critical |
| Certification and Compliance | Product, quality, environmental, and application-specific compliance | Certificates must match the actual manufacturing site, product scope, validity period, and purchased material. Third-party inspection may be appropriate for high-risk orders. | Valid certificates, declaration of conformity, inspection release note, and third-party inspection report where applicable. | High |
| Packaging and Protection | Moisture protection, edge protection, bundle stability, and corrosion prevention | Packaging should reflect the transport route, storage period, surface finish, and risk of chloride or moisture contamination. | Packaging specification, loading photographs, marking format, and handling instructions. | Medium |
| Delivery Reliability | Lead time, on-time delivery, minimum order quantity, and production flexibility | Assess performance using documented delivery history for comparable specifications rather than a general delivery promise. | Recent delivery-performance data, production lead-time schedule, order references, and escalation procedure. | High |
| Technical Support | Specification review, material selection, claim handling, and engineering communication | A capable supplier should identify conflicts between grade, thickness, finish, forming requirements, corrosion environment, and applicable standards before production. | Technical questionnaire, sample contract review, engineering contact details, and claim-resolution procedure. | Medium |
| Sustainability and Energy Data | Recycled content, energy management, emissions reporting, and environmental controls | Environmental claims should be supported by defined boundaries, recognized certifications, or independently verified data rather than general marketing statements. | Environmental certificates, product carbon-footprint methodology, recycled-content declaration, and audit evidence. | Medium |
| Supplier Qualification Score | Weighted evaluation of quality, capacity, technology, compliance, service, and cost | Use a documented scoring model. For critical applications, quality and traceability should receive greater weight than unit price alone. | Completed supplier questionnaire, audit report, trial-order results, non-conformance rate, and final approval record. | Critical |