Flat or plate fins are used in the heavy-duty heat exchangers where strength of the core is important.
These fins can be made from several materials such as copper, brass, steel, or aluminum. There are hundreds of designs for this type of fin, varying the tube size, tube pitch, tube row spacing and with features such as louvers, dimples, stiffeners, that make them work for many purposes. Due to the many applications for this fin the fin material can be as thin as 38 microns to as thick as 0.25mm. Additional options to help strengthen the core face include steel or brass edges.