I am trying provide Customs with a tariff code for a helical spring of steel wire. The Harmonized Tariff Schedule asks for the "cross-sectional dimension" of the spring. I have been told that this is not the same as the diameter. Does anyone know how i can find the "cross-sectional dimension" of a spring with an inside diameter of 4.7 mm and an outside diameter of 5.3 mm? Not sure you would need it, but the height is 12.4 mm. Any help would be greatly appreciated. Thank you.