Enter the length of the bend, the tensile strength, material thickness, and unsupported material length into the calculator to determine the bend force.

## Bend Force Formula

The following equation is used to calculate the Bend Force.

BF = (k*L*St*t^2) / d

• Where BF is the bend force (lbs)
• k is a constant based on the die shape (1.33 for V dies)
• L is the length of the bend (in)
• St is the tensile strength of the material (lb/in^2)
• d is the unsupported material (die opening) (in)

## What is a Bend Force?

Definition:

A bending force is a total force required to bend a material with a particular die shape and opening.

## How to Calculate Bend Force?

Example Problem:

The following example outlines the steps and information needed to calculate Bend Force.

First, determine the k constant. In this example, we are using a v die, so the constant is 1.33.

Next, determine the length of the bend. This bend is measured to be 3 inches.

Next, determine the tensile strength of the material. The tensile strength is calculated to be 50 lbs/in^2.

Next, determine the material thickness. In this case, the material thickness is 1.5 inches.

Next, determine the die opening size. For this problem, the unsupported material is 8 times the thickness = 12 inches.

Finally, calculate the bend force using the formula above:

BF = (k*L*St*t^2) / d

BF = (1.33*3*50*1.5^2) / 12

BF = 37.406 lbs