Railway parts must adhere to stringent safety and performance standards. You should prioritize suppliers with ISO/TS 22163 (IRIS - International Railway Industry Standard) certification, which is the global benchmark for railway quality management. Additionally, ensure products meet regional technical specifications such as EN 13261 for axles, EN 13262 for wheels, and AAR (Association of American Railroads) standards if exporting to North America. For welding components, EN 15085 certification is mandatory to ensure structural integrity.