Enter the k constant (die factor), the length of the bend, the tensile strength, the material thickness, and the die opening (unsupported span) into the calculator to determine the bend force.

Bend Force Calculator

Enter any 5 values to calculate the missing variable










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 (lbf)
  • 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 (psi, i.e., lbf/in²)
  • t is the material thickness (in)
  • d is the unsupported span / 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. For this example, assume a tensile strength of 50,000 lb/in² (50,000 psi, which is 50 ksi).

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 span 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*50,000*1.5^2) / 12

BF = 37,406.25 lbs