Brazing — What It Is and Why It Matters
Brazing is a metal-joining process that uses a filler metal with a melting point above 840°F (450°C) but below the melting point of the base metals being joined. The filler is drawn into the joint by capillary action, creating a strong metallurgical bond without melting the parent material.
Brazing differs from welding in that the base metals are not melted, and from soldering in that brazing temperatures are higher (soldering uses filler metals below 840°F). Common brazing filler metals include silver alloys (silver brazing), copper-phosphorus alloys, and nickel alloys for high-temperature applications.
The process is widely used for joining dissimilar metals, assembling HVAC copper tubing, carbide tool tip attachment, bicycle frame construction, and jewelry making. Brazed joints can be stronger than the base metals themselves when properly executed, because the filler metal wets and bonds with both surfaces at a molecular level.
Frequently Asked Questions
Is brazing as strong as welding?
A properly made brazed joint can approach or exceed the strength of the base metals. The joint design matters — brazing works best with close-fitting lap joints that maximize the bonded surface area. For structural loads, welding is generally preferred, but brazing excels for joining dissimilar metals and thin or heat-sensitive parts.
What is the difference between brazing and soldering?
Temperature. Brazing uses filler metals that melt above 840°F (450°C), while soldering uses filler metals below that threshold. Brazing produces stronger joints and is used for structural and plumbing applications; soldering is used for electronics and light-duty copper plumbing.