What do F-numbers classify in welding?

F-numbers are part of the classification system used for filler metals in the context of welding. The F-number specifically provides information on the usability characteristics of the filler metal, which includes aspects such as the type of welding processes it is compatible with, the position in which it can be welded, and how it behaves during the welding operation. This classification helps welders select the appropriate filler metal for specific welding applications, ensuring quality and consistency in the welds produced. Understanding F-numbers is essential for achieving the desired mechanical properties and preventing issues such as cracking or inadequate penetration in the weld joint.

Base metals, welding defects, and welding processes are categorized differently and do not fall under the classification of F-numbers, which is specifically aimed at filler metals.