How can you identify the material used in a given tube fitting?

Identifying the material used in a tube fitting is best achieved through the material code letter associated with that fitting. Each material has a specific code that denotes what it is made from, such as steel, stainless steel, plastic, or brass. This code provides a quick reference that helps users determine the appropriate usage conditions and compatibility with different fluids or environments.

While factors such as color code and shape may provide some information, they are not reliable indicators of the material itself. Color codes can vary across manufacturers and are not standardized, which can lead to confusion. Dash numbers often relate to the fitting size or thread type, rather than the material composition. Similarly, the shape of the fitting might denote a style or connection type but does not indicate the material it is constructed from. Therefore, the material code letter remains the most accurate and reliable way to identify the material of a tube fitting.