Definition
A method of joining two pieces of metal by heating them and flowing molten copper between them. The copper acts as a filler that bonds to both surfaces as it cools, forming a strong joint without melting the parent metals. Commonly used in the manufacture of aircraft engine and airframe components such as steel tubing assemblies.
Plain English
Sticking two metal parts together by melting copper between them. The copper acts like a strong glue that hardens as it cools, holding the parts firmly without melting the parts themselves.
Context Anchor
Seen in aircraft maintenance and repair descriptions, especially when discussing how certain metal parts were joined or repaired.
Derivation
Brazing comes from the Old English and Germanic root meaning 'to harden by fire,' and is related to 'brass' — historically the filler metal used. The word survived into modern usage to describe any process that joins metals using a melted filler that flows between them. Calling it 'copper brazing' simply specifies that copper is the filler.
Why Pilots Care
Pilots don't perform brazing, but they should recognize it on inspection. A brazed joint that shows cracking, discoloration, or separation is a maintenance discrepancy that must be addressed before flight, particularly on engine mounts and steel tube structures.
Intuition Check
Copper brazing is not the same as welding. In copper brazing, the copper filler melts and bonds the joint; the main metal parts are not melted together.
Example Sentence 1
The steel tube fuselage cluster joints were copper brazed at the factory and inspected for cracks during the annual.
Example Sentence 2
Copper brazing created a strong, leak-proof joint that could withstand engine operating temperatures.