Enter the grout hole diameter and the length of the hole into the calculator to determine the bolt pull out force.

## Bolt Pull Out Force Formula

The following equation is used to calculate the Bolt Pull Out Force.

Fpo = D*PI*L*MF
• Where Fpo is the bolt pull out force (lb-f)
• D is the diameter of the hole (in)
• L is the length of the hole (in)
• MF is a material bond factor
• = 600 for epoxy to concrete bond
• = 1600 for epoxy to steel bond

To calculate a bolt pull out force, multiply the diameter by the length times pi, then finally multiply by the material bond factor.

## What is a Bolt Pull Out Force?

Definition:

A bolt pull-out force is the amount of weight applied to a bolt to remove it from the material it is piercing. It measures the combined strength of the bolt and joint in shear.

## How to Calculate Bolt Pull Out Force?

Example Problem:

The following example outlines the steps and information needed to calculate the Bolt Pull Out Force.

First, determine the diameter of the hole. In this example, the hole diameter is 2.5 inches.

Next, determine the length of the hole. In this case, the length is 5 inches.

Next, determine the material bond factor. For this problem, the bond is between epoxy and concrete, so the bond factor is 600 PSI.

Finally, calculate the bolt pull out force using the formula above:

Fpo = D*PI*L*MF

Fpo = 2.5*3.14159*5*600

Fpo = 23,961.625 lb-f