Originally Posted by
calstar
So the only reason butted tubes are thicker at the ends is to deal with the heat/stress of brazing? Does the tigged straight gauge frame use smaller wall thickness at the ends than the butted(given = tube od)?
The HAZ for TIG welding is smaller, so the butts are shorter. That's why the True Temper catalog has so many tubes with ridiculously short butts, those tubes are intended for TIG. As far as the nature of the transition, as long as it's smooth it doesn't really matter much.