Soldering and brazing are processes used to join metals by melting a filler material that flows into the joint between the workpieces. The temperature at which these processes are performed is critical because it influences the properties of the joint created.
In soldering, the melting point of the filler material is generally below 840 degrees Fahrenheit, making it effective for joining materials like copper, brass, and certain types of steel, often for electronics and plumbing applications. This lower temperature is useful to avoid damaging the base metals.
Brazing, on the other hand, requires higher temperatures, typically above 840 degrees Fahrenheit and can go up to about 1000 degrees Fahrenheit or even higher, depending on the specific filler material used. The temperature mentioned in the correct answer represents the boundary where brazing starts to occur effectively, enabling a stronger joint than soldering due to the additional heat that allows for diffusion of the materials involved.
Choosing 840 degrees Fahrenheit is significant because it underscores the transition point between soldering and brazing. It signifies that brazing can successfully occur at this temperature, making it a standard benchmark within the context of this question.