What are P-numbers used for in welding?

P-numbers are specifically used to classify base metals in welding. This classification system helps in the development of welding procedures and ensures consistency in welding practices. The P-number categorizes materials with similar properties, enabling welders to use a standardized set of techniques, parameters, and filler materials when working with these metals, thus promoting efficiency and ensuring the integrity of welded joints.

Understanding the P-number system allows welders to determine suitable preheat and post-weld heat treatment requirements, as well as other essential aspects of the welding process based on the base metal's characteristics. By using this classification, welders can also refer to existing qualified welding procedures for welding similar materials, ultimately enhancing their skill set and safety in the welding environment.