I have had the same issues on some parts doing bends under 90 degrees. I have been using bend deduction, but I am going to change to using k-factor. The issue that I am having is that I don't know how to calculate it! Because it says you need BA to get the k-Factor, but you need the k-factor to get the BA. Our bend radius is .0313 and we bend AL from .0313 upto .19.