If you have a Bend Allowance (BA) you can derive the K-Factor from it. Because of this it is often used by design software such as Solid Edge, Solid Works and Pro-Engineer, though Pro-Engineer uses a variation called the Y-Factor. Having an accurate idea of your K-Factor is key to designing good parts because it can anticipate Bend Deductions for a variety of angles without relying on a chart. It’s used to determine Bend Allowances and Bend Deductions ahead of the first piece. The K-Factor is used to calculate flat patterns because it is directly related to how much material is stretched during the bend. Below the image shows how the top of the bend is compressed, and the bottom is stretched. The K-Factor is the ratio of the Neutral Axis’ Offset (t) and the Material Thickness (MT). The location of the neutral axis varies and is based on the material’s physical properties and its thickness. The line where the transition from compression to stretching occurs is called the neutral axis. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. The K-Factor in sheet metal working is the ratio of the neutral axis to the material thickness.
