The fin is not attached to the tube — it is formed from a sleeve that becomes part of the tube. A softened aluminium or copper sleeve is fitted over the base tube and passed through three rotating extrusion rollers. The rollers squeeze the sleeve onto the tube and raise the fins from the same material, so the fin, the liner and the base tube stay in permanent contact without solder, glue or filler.
Because the bond is mechanical and continuous, extruded fin tubes keep their air-side performance after repeated thermal cycling. Fins cannot unwind or loosen, which is why this construction is the default for air-cooled heat exchangers, fin-fan coolers, compressor aftercoolers, HVAC coils and greenhouse heating.
Typical specification: base tubes in carbon steel A179/A192, stainless 304/316L, copper, copper-nickel or alloy steel; aluminium 1050/1060/3003 or copper fins; continuous service up to 250 °C; fin height and pitch to customer drawing.
Tell us the base tube standard and material, tube OD and wall thickness, fin material, fin height, fin pitch, finned and total length, and quantity. If you only have a duty — kW, flow rates and temperatures — our engineers will select the tube for you.
Related: Extruded (Bimetal) Finned Tube · Embedded G-Type Fin Production · High Frequency Welded Fin Production