Depending on working temperature you can differentiate between soft soldering and hard soldering.
In soft soldering the working temperature is below 450 °C. Soft soldering is suited to copper and copper alloys, zinc, steel aluminum and aluminum alloys; tin solder is most commonly used.
In hard soldering, the solder’sworking temperature is higher than 450 °C but no higher than ca. 1000 °C. A flame is usually employed as the heat source. Hard soldering is the most common form of soldering and is well-suited to most metals. Hard soldering is used, for example, for joining copper pipes in the production of bathroom fixtures and for fastening pieces of hard metal to saw blades and drill bits.
In both hard and soft soldering, the solder is sucked in between the surfaces to be joined through capillary action. It is therefore important for the distance between the surfaces to be joined to be correctly dimensioned.
Soft and hard soldering can be automated and are therefore often used in series production.
Soldering does no presuppose the same high working temperature as welding, which gives rise to fewer problems with deformations. Soldering provides joints of high quality and high surface finish.
An oxy-fuel gas flame is used in soldering, with acetylene or propane being the most common gases.
Avoid risks by following the safety instructions for hot work.