What’s the difference between brazing and soldering?

Brazing and soldering are both methods used to join two or more metal components together, but they differ in terms of temperature, filler material, and the strength of the joint produced. Here are the key differences between brazing and soldering:

1. Temperature: Brazing involves heating the metal components to significantly higher temperatures compared to soldering. The brazing process typically requires temperatures above 450°C (840°F), while soldering is performed at lower temperatures below 450°C (840°F).
3. Filler Material: In brazing, a filler material with a higher melting point is used (typically a brass or silver alloy), which is then heated to melt and flow into the joint, forming a strong bond. Soldering, on the other hand, uses a lower melting point filler material, known as solder (often a lead-tin or lead-free alloy), which melts and coats the joint through capillary action.
5. Strength: Brazing generally produces stronger joints compared to soldering. The higher temperatures used in brazing enable the filler material to bond more closely with the base metal, resulting in a stronger joint capable of withstanding higher mechanical stresses. Soldered joints are generally weaker and more suitable for lighter applications or electrical connections.
7. Application: Brazing is commonly used for applications where high joint strength is required, such as in the automotive, aerospace, and plumbing industries, as well as in the production of heat exchangers and metal sculptures. Soldering is typically used for electrical connections, electronics, jewelry making, and other light-duty applications.
9. Surface Preparation: Brazing typically requires more rigorous surface preparation, including cleaning and flux application, to ensure proper bonding. Soldering generally requires less stringent surface preparation and relies on the flux within the solder to clean the joint during the soldering process.

It’s important to note that local regulations regarding the use of lead-based solders may vary, and the shift towards lead-free soldering has become more prevalent due to environmental concerns.