What is the primary purpose of a flux in soldering?

The primary purpose of flux in soldering is to chemically clean the surface of the fittings. Flux is a chemical cleaning agent that removes oxidation and other contaminants from the metal surfaces being joined. This cleaning action is essential because it allows for better wetting of the solder to the metal surfaces, ensuring a strong and reliable bond. A clean joint helps the solder flow smoothly into the spaces between the surfaces, resulting in a more effective connection.

In the context of soldering, if surfaces are not properly cleaned, oxidation can prevent the solder from adhering effectively, leading to weak joints that may fail under stress or over time. Therefore, using an appropriate flux is crucial for successful soldering operations.