In bending, residual stresses cause the material to spring back slightly after the bending operation. Due to this elastic recovery, it is necessary to over-bend a precise amount to achieve the desired bend radius and bend angle. The final bend radius will be greater than initially formed and the final bend angle will be smaller. The ratio of the final bend angle to the initial bend angle is defined as the springback factor, Ks. The amount of springback depends upon several factors, including the material, bending operation, and the initial bend angle and bend radius.