Originally Posted by Scooper
As Nessism says, lugged steel bikes are brazed, often with a brazing alloy that's from 45% to 56% silver because of the advantages of using lower brazing temperatures on many of the steels commonly used for bicycle frame tubing.
FYI, there is no real advantage of using silver brazing alloys over brass other than marginally easier repairability. Reynolds 753 was the only alloy that really needed silver...and those tubesets are not produced anymore. Brass brazing temperatures, while higher than silver, don't take enough temper out of the tubes to matter. That said, most investment cast lug sets these days fit quite closely on the tubes, and since they fit so tight, the clearance is most suitable for silver since the gap requirements are tighter. Not sure what this adds to the discussion but I felt like sharing.
