Many factors are taken into consideration when deciding which grade of stainless steel tubes to choose from. The crucial feature for stainless steels is that they are immune to corrosion for a given application or environment. Strength and fabrication features are also taken into consideration. There are more than 60 grades of stainless steel available. Nevertheless, the entire group may be divided into four metallurgic groups. In order to decide the grade to be selected, certain mechanical or physical properties will also need to be included in order to satisfy the overall service performance requirements.