Flux is a chemical cleaning agent used in plumbing, metalworking, and electronics to facilitate the joining of metal parts through soldering, brazing, or welding. In plumbing, flux is applied to copper pipes and fittings before soldering to remove oxidation and impurities, ensuring a strong, leak-proof bond. Available in paste, liquid, or powder forms, flux helps prevent corrosion and enhances the flow of solder into the joint. It is an essential component in achieving durable, reliable connections in various metalworking applications.