Bend Allowance Chart

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What Is Bend Allowance?

Bend allowance is an essential parameter in order to obtain the accurate press brake bending workpiece.

After bending, the metal sheet will stretch outside and compress inside under the influence of tension and pressure.

Therefore, bend allowance and bend deduction should be considered in the flat pattern of the workpiece to obtain the final accurate bending workpiece.

Both the bend allowance and the bend deduction are used to calculate the dimensions of the flat workpiece drawing.

The bend allowance refers to the length of the neutral axis between the bending lines, and the length added to the flange length is the bend allowance.

The value of the bend allowance is the difference between the total flat length and the total flange length of the workpiece in the flat pattern mode.

To calculate the bend allowance, we need to know the plate thickness, bending angle, internal radius, K factor, and other parameters.

The K factor refers to the ratio of the neutral axis position to the plate thickness. Different plates have different K factors.

Bend Allowance Calculation

The bend allowance calculation formula is:

Where B is the bending angle, IR is the inner radius, and MT is the thickness of the plate, K is the K factor.

Bend Allowance Chart

In addition to the bend allowance formula, it can also be determined through the bend allowance chart.


When the bend allowance is known, the bend deduction can be obtained. These two parameters are necessary for obtaining accurate workpieces.

You can calculate the bending allowance by the above formula, or you can use the bend allowance chart.

If you want to know more about bending, you can read our blog and browse our press brake products.

In addition to press brakes, ADH products also manufacture panel benders, laser cutting machines, shearing machines, etc. If necessary, you can contact our product experts.

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