What is the difference between a "traditional lugged" steel frame and the "butted" frame referenced above?
A lugged frame uses "lugs" that the tubes fit into and are then "brazed" in place (low heat welding basically)
Image of a BB lug;
http://www.ceeway.com/Graphicpages/0...SHELLS2003.gif
Butted frames are when the frame tubing is "butted" against each other and then welded in place.