The properties of a boiler tube are dependent only upon the geometry and material of construction. The only thermal property of interest for a plain wall tube is the thermal conductivity at the temperature of interest, which provides a means of calculating the thermal resistance for conduction through the wall. If the boiler tube is finned on the outside then the geometry and application data will provide a means to determine the total extended surface area and the fin efficiency. Two good references for boiler applications are Process Heat Transfer by Hewitt, Shires and Bott and Steam – Its Generation and Use by Babcock & Wilcox.