Quality validation should involve both document review and physical testing. Request Third-Party Inspection (TPI) from agencies like SGS or BV to conduct Non-Destructive Testing (NDT), such as Ultrasonic or Magnetic Particle inspections, to detect internal flaws. Additionally, perform Dimensional Tolerance Checks to ensure the thickness, width, and length meet the specified ± tolerances. For coated steel (like Galvanized), use a Coating Thickness Gauge to verify the zinc layer (e.g., Z275) meets the anti-corrosion requirements.