I am designing a part that needs a 10in radius bend in 11ga mild steel. Due to the nature of the part I cannot roll it. To increase speed of manufacture and bend surface quality, I would like to try and bend this part in one shot. So I would rather not bump form if I can avoid it. I am having troubles finding any calculations to calculate sprinback and final radius of such a large bend. I need this so I can design a die with the correct initial radius to result in a final 10in radius. Any of the equations I have used do not give me an answer I am confident will work. Can anyone point me to a calculation for very large profound radius bends?