I just pulled this from the Web - it was the first non-commercial hit when I Googled for brazing. They are referring to volume-production, Industrial-type applications, but the facts are the same for brazing bicycle frames. Some post-brazing cleanup my be required for frames, though! (Well, maybe not, for Production bikes built during the '70s bike boom). ;-) Greg Parker Ann Arbor, Michigan
What is brazing? Brazing is the joining of metals through the use of heat and a filler metal one whose melting temperature is above 840°F(450°C) but below the melting point of the metals being joined. (A more exact name for the brazing process discussed in this book may be "silver brazing," since in most cases the filler metal used is a silver alloy. To remain brief, we'll use the term "brazing" throughout this book, with the understanding that we are referring to a torch brazing process with a silver-bearing filler metal. Where exceptions occur, it will be noted.) Brazing is probably the most versatile method of metal joining today, for a number of reasons. Brazed joints are strong. On non- ferrous metals and steels, the tensile strength of a properly made joint will often exceed that of the metals joined. On stainless steels, it is possible to develop a joint whose tensile strength is 130,000 pounds per square inch. ( 896.3 megapascal [MPa] ). Brazed joints are ductile, able to withstand considerable shock and vibration. Brazed joints are usually easy and rapidly made, with operator skill readily acquired. Brazing is ideally suited to the joining of dissimilar metals. You can easily join assemblies that combine ferrous with nonferrous metals, and metals with widely varying melting points. Brazing is essentially a one-operation process. There is seldom any need for grinding, filing or mechanical finishing after the joint is completed. Brazing is performed at relatively low temperatures, reducing the possibility of warping, overheating or melting the metals being joined. Brazing is economical. The cost- per-joint compares quite favorably with joints made by other metal joining methods. Brazing is highly adaptable to automated methods. The flexibility of the brazing process enables you to match your production techniques very closely to your production requirements. With all its advantages, brazing is still only one of the ways in which you can join metals. To use brazing properly, you must understand its relationship to other metal jointing methods. What are some of those methods and which should you use where? The versatility of brazing. Strong joints Ductile joints Ease of operation Suited to dissimilar metals One-operation process Requires low temperatures Economical Highly adaptable to automation