What is the advantage of using flux during soldering?

Using flux during soldering is crucial because it ensures a better joint by removing oxidation from the surfaces to be joined. When metal surfaces are exposed to air, they can develop an oxide layer, which can impede the adhesion of the solder. Flux acts as a cleaning agent that removes these oxides and other contaminants, allowing for a cleaner surface for the solder to bond to. This results in a stronger and more reliable joint, which is essential in pipe fitting and other soldering applications.

The other choices highlight points that do not accurately align with the principal function of flux in soldering. While flux can assist in making the process cleaner by reducing the need for extensive cleaning, its primary role is in enhancing the bond by preparing the metal surfaces. Hence, the effectiveness of the solder joint significantly depends on the presence of flux to facilitate a strong connection.