Originally Posted by Doug Fattic

Pinning tubes together to hold their position is not a universal practice among all frames builders. Where I learned to build frames at Ellis Briggs in Yorkshire, we pinned frames there while the frame was being held in a fixture that was based on a cast iron flat table insuring that the frame started out in alignment. Pinning was necessary because the frames were hearth brazed together. This is a process where a giant natural gas flame (way bigger than even a rosebud flame) is augmented with air oxygen supplied with a squirrel cage. Both head tube lugs would get up to cherry red brass brazing temperature before the brass was applied. In this case the frame needed to be mechanically held together or its design and alignment would probably be lost.

When I got back to the States and started brazing with silver and an airline torch, I no longer pinned my frames. I didn't need to. Your question opens up the bigger question on how frames are made by different builders and the philosophies behind them. These are often driven by the kind of equipment we own, Tread carefully here because each builder is going to think their way is best or they would do it another better way. The goal when brazing is to do it as quickly as possible and keep the original design intact and end up with the tubes aligned. It is really easy to get into the weeds here.