Bending Terms
Bend Allowance
The length of material that will be deformed during the bend. It is strongly recommended to avoid placing holes or other cutouts in the bend allowance region—unless they are centered directly under the bend line. Otherwise, the bend will be pulled toward the holes, changing the size of the finished part.
Bend Angle
The angle between the two flanges of the bent part. Values less than 90 degrees are more closed (acute), and values between 90 and 180 degrees are more open.
Bend Deduction
The difference between the final dimensions of the bent part, as measured on the outer surface, and the original size of the flat part. This value is often used to calculate the size of the flat that will result in a desired final dimension. For example, to create an L-bracket where each side is 6 inches long, if the bend deduction is 0.5 inch, the flat part should be 11.5 inches long.
Bend Line
The line where the punch will contact the part. When you select a line in your drawing to be bent, we will position the punch on that line.
Inner Radius
The approximate radius of the inside of the bend. Bends are not exactly circular, so this value is more of a design parameter, rather than an actual measurement.
K-factor
A coefficient that describes the location of the neutral axis. It is a measure of the tendency of the material to either compress or stretch during bending. The K-factor is around 0.4 for soft metals like aluminum, and around 0.45 for harder metals like steel and stainless.
Minimum Flange Support
The minimum distance between the bend line and the edge of the material. Material within the minimum flange support region will contact the die during bending. A larger bend radius uses a larger die, so it requires more flange support. We recommend minimizing the number of holes or other cutouts in the flange support region, to ensure the most accurate bends.
Maximum Bend Length
The maximum length of a bend that can be made with a certain inner radius. This is limited by both the physical size and tonnage capacity of our press brake.
Neutral Axis
The point in the interior of the material that neither stretches not compresses during bending.
Outside Setback
In the finished part, the distance from the beginning of the bend allowance region to the outer surface of the flange.
