The certification mark, as intended to be used by authorized persons, is intended to certify that the product meets the Steel Tube Institute of North America's certification process requiring an engineering evaluation and testing of samples. The testing process takes place no less than once per year and this includes review of receiving records of steel coils, production processes, post production reports and obtaining and testing samples of the manufactured products; all testing is to confirm that the steel products meet the ASTM (American Society for Testing Materials) standards for steel.