... be made by material of copper, copper alloy, carbon, aluminum, titanium or double material mixed A) Our finned tube included ... bellowing materials:1) Aluminum extruded fin tube, base material is carbon steel SA179, or stainless ... alloy C70600, C71500, C70400 and Brass C44300, C687004) Economizer fin tube, in material of carbon steel SA179, or stainless steel ...