How to calculate depth of bend on press brake?

The bend depth of the press brake ram is calculated and controlled when the sheet is bent at a certain angle by free bending on the press brake machine.

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, there are many factors that affect the bending angle of the sheet material.

The measured angle of the first bending often does not match the set angle and needs to be corrected.

At this time, the angular error should be converted into the depth correction value to make it corrected.

Calculated by using the formula for the bend depth of the ram for free bending and the formula for correcting the depth of the ram in case of angular error, we have simplified it into a practical formula that can be applied practically at the production site.

We have made it into an online calculator for your convenience and hope it will help you.

**When the punch tip angle is 85°/88°**

## When the punch tip angle is 28°/58°

**Remarks:**

- The above calculation is based on free bending
- The lower die opening V during free bending shall generally be equal to 8 ~ 12 times the plate thickness t.
- For the sheet thickness t in the formula, if the sheet thickness thinning caused by plastic deformation of the bent material is considered, t shall be replaced by nt. n is the material thinning coefficient, generally n = 0.98 ~ 0.99

EsterI 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?

MachineMfgHope the calculator that we made can be useful for you.

chiragyou 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)

ShaneActually, it’s much more complicated than this.

AlexandruI 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.

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

KevinWill there be a version in inch in order to eliminate additional steps?

ShaneGood suggestion, we will take it into consideration, so stay tuned.

KevinAlso, thank you for making this!

ShaneYou’re welcome.

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