Solder ring fittings are used to make joints between copper pipework with heat using a blow torch. The fittings are ideal for use in heating systems, hot and cold water systems including drinking water. The fittings have a ring of solder embedded in the collar of the fitting which when heated to melting point liquifies and on cooling forms a strong and secure joint around the pipework. This is sometimes known as sweating or brazing. Pipe and fitting ends must be cleaned with a suitable product such as wire wool or cleaning strips, and flux must be used removing impurities before brazing the fitting.