Relative wall thickness = wall thickness / external bend radius, however, it is really the same thing reversed. Note: In some literature on the subject there is the inverted ratio calculation: Wall Factor (WF) = the outside diameter OD / thickness of the walls WT. Generally we can say that tubes with a relative WT below 10 are considered to be strong walled (thick walled) and conversely with a relative WT higher than 40 are thin walled. The resulting value then determines whether it is a thin-walled or a thick-walled tube. This is the relationship of the outside diameter and the thickness of the walls of the tubes.
Wall Factor (WF) - the relative thickness of the wall. Using a variety of parameters, we can judge the difficulty of the bend and suggest the best set of tools for a given application.
