Estimate ideal cylinder axial force, pressure or bore diameter using an explicit solve mode, or compare extension and retraction for a rod cylinder. Enter nonnegative pressure and force magnitudes and positive diameters, then select Calculate.

Ideal pressure force on a circular full-bore area. Enter nonnegative pressure and force magnitudes; diameter must be positive.

Pressure above the unpressurized side. Suggested values are input shortcuts, not equipment ratings.

Axial Force Formula

The following equation gives ideal pressure force on a full circular bore area. It excludes friction, seal losses, back pressure, acceleration and buckling; it is not a safe working load or equipment rating.

AF = P × pi × d² / 4
  • Where AF is the axial force (lb-f)
  • P is gauge pressure above the unpressurized side (lb-f/in2, i.e., psi)
  • d is the cylinder internal diameter (in)

To calculate ideal axial force, multiply gauge pressure by π times the internal bore diameter squared over 4. Pressure mode uses P = F/A, and bore mode uses D = 2√(F/(πP)). Rod-cylinder mode uses the full bore area for extension and π(D² − drod²)/4 for retraction, with the same gauge pressure applied separately in each direction and zero opposite-port gauge pressure. The rod must be smaller than the bore. Unit changes convert the entered quantity; pressure and diameter suggestions are conveniences, not ratings.

What is an Axial Force?

Definition:

A force is said to be an axial force if applied along the body’s axis. In engineering and physics, it is essential to identify the type of force acting on a body.

An axial force can be either a tensile or a compressive force. If the axial force tends to pull the body apart, it is a tensile force. On the other hand, if the axial force tends to compress or squeeze the body, it is known as a compressive force.

Typically axial forces are used to describe the forces acting along a tube’s axis under internal or external pressure.

How to Calculate Axial Force?

Example Problem:

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

First, determine the gauge pressure. In this example, 500 psi acts on the full bore with the other side unpressurized.

Next, determine the diameter of the tube. For this problem, the cylinder has a diameter of 5 inches.

Finally, calculate the axial force using the formula above:

AF = P * pi*d^2/4

AF = 500 × π × 5² / 4

AF ≈ 9,817.48 lbf (≈ 43,670.31 N)