For formed structural members (e.g. an angle rolled into a circular ring), weldment cutlists appear to report LENGTH based on the diameter at the mean height dimension of the profile. However, I believe the length should be based on the diameter at the neutral axis of the profile. This would not matter for shapes that are symmetric with respect to the axis they are bent about, but for members such as angles and WT's the difference can be significant.
For example, take an L4x4x1/2 angle "rolled the hard way" to 100" inside diameter. Solidworks will calculate the cut length as L=pi*(100"+(2)2") = 326.73". If you calculate the length about the neutral axis you get L = pi*(100"+2(2.82") = 331.88". The difference is more than 5".
My question is, do others agree that the length should be calculated based on the diameter to the neutral axis? Wanted to get some feedback before I accuse Solidworks of doing it wrong.