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Press Brake Bending Depth Calculator (Punch Penetration Depth)

How to calculate the depth of the bend (or the penetration depth of the punch into the die) on a press brake with a given bending angle, measured angle, sheet thickness, and die opening?

The penetration depth of the punch into the press brake die is calculated and controlled when the sheet is bent at a certain angle by air bending on the press brake machine.

Press Brake Ram Depth Calculator

This is to control the positioning value of the ram when moving up and down.

The upper die mounted on the ram will bend the sheet to a certain position exactly at the sum of the certain set angle and the rebound angle. In this way, the workpiece can spring back to the set angle after the ram returns.

However, in actual bending, many factors affect the bending angle of the sheet material. The measured angle of the first bend often does not match the set angle and needs correction. At this point, the angular error should be converted into the depth correction value.

To achieve this, the bend depth formula of the ram for air bending and the formula for correcting the depth of the ram in case of angular error are used. These formulas have been simplified into a practical formula that can be applied at the production site.

For your convenience, we have created an online calculator, which we hope will be useful to you.

When the punch tip angle is 85°/88°

When the punch tip angle is 28°/58°


  • The above calculation is based on air bending
  • During air bending, the lower die opening V should generally be equal to 8~12 times the plate thickness t.
  • In the formula, for the sheet thickness t, if the thinning caused by plastic deformation of the bent material is considered, t should be replaced by nt. The material thinning coefficient is represented by n, which is generally between 0.98 and 0.99.

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14 thoughts on “Press Brake Bending Depth Calculator (Punch Penetration Depth)”

  1. I am looking for the formula to calculate the theoratic depth of the ram to get a certain angle.
    But I have a hard time finding this.

    Can you help me with this?

    1. you can use trigonometric tan(theeta) equation for find the depth of ram.

      tan(x)= opp/adj

      you have angle x, how much want to band
      you have opp side as the v opening
      so, you can find depth….adj…
      adj=tan(x)(require bend angle) *opp(v-opening)

  2. I ask for the formula too, i have a old press brake and i need to retrofit. Please give the formula for all is interested. Thank you.

    1. Sorry we can’t provide you the formula, you can use this online calculator anytime if it is useful for you.


    Thank you for making this calculator. However, is it possible to show the variables of the equation in the figure?

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