... as brass, cupronickel, carbon steel,ti,etc. The extruded finned tubes are formed in a cold rotary extrusion process, where ... serrated fins can be effected. Extruded Bi-metalic Aluminium finned tubes for construction of heat exchangers for the range of ... or copper.Bare Tubes Materials:Bare tubes can be of any material such as brass, cupronickel, carbon steel, stainless steel, titanium, nickel alloy, ...