What quality inspections should I require before a shipment leaves China?

For construction materials and metals, the inspection stages buyers typically require are: - **Initial Production Check (IPC):** Verifies raw materials and the first 10-20% of production against spec. Catches wrong steel grade, incorrect coatings, or wrong dimensions before the full run. - **During Production Check (DUPRO):** Performed at 40-60% completion. Confirms the run is consistent and dimensional tolerances are holding. - **Pre-Shipment Inspection (PSI):** Performed when 80-100% of goods are packed. Inspector pulls samples per AQL (Acceptable Quality Limit) standards - typically AQL 2.5 for major defects, 4.0 for minor - and confirms quantity, packing, marks, and loading. - **Container loading supervision:** Inspector witnesses the actual loading to prevent substitution. For steel specifically, also require: - **Mill Test Certificates (MTCs)** for every heat/batch showing chemical composition and mechanical properties. - **Third-party lab tests** (tensile, yield, elongation, bend test) on random samples if the destination country requires it (e.g. SONCAP, SABS). - **Coating thickness checks** for galvanised and pre-painted products. SGS, BV, TÜV, and Intertek are the four agencies most commonly accepted by African and Middle Eastern customs authorities. Costs typically run USD 300-500 per inspection day.