There are some details in the catalogues, but I wonder what you guys mean when you say single-butted?
A 9-6-9 tube on a Lava Dome/Cinder Cone is a double-butted tube. A 10-7-10 tube on a Fire Mountain is also double-butted, but heavier. If a maker describes a frame as single-butted, as far as I am aware they are referring to the 'best' tube. The only single butted tube you'll find is a seat tube of 10-7. So my guess is that a 'single-butted frame' has a single-butted seat tube and plain-gauge top and down tubes. Maybe that's what you mean about a Hahanna?
A 9-6-9 tube on a Lava Dome/Cinder Cone is a double-butted tube. A 10-7-10 tube on a Fire Mountain is also double-butted, but heavier. If a maker describes a frame as single-butted, as far as I am aware they are referring to the 'best' tube. The only single butted tube you'll find is a seat tube of 10-7. So my guess is that a 'single-butted frame' has a single-butted seat tube and plain-gauge top and down tubes. Maybe that's what you mean about a Hahanna?