Extrusion Ratio

What is this formula?

The Extrusion Ratio measures the reduction in cross-sectional area that occurs during an extrusion process. It is defined as the ratio between the initial billet area and the final extruded product area. Higher extrusion ratios generally require greater extrusion forces and result in larger material deformation.

When to use it

Use this formula when designing extrusion operations, estimating forming loads, evaluating process feasibility, or comparing different extrusion geometries.

Example

An aluminum billet with an initial cross-sectional area of 5000 mm² is extruded into a profile with a final cross-sectional area of 625 mm².

Data:

A0 = 5000 mm²

Af = 625 mm²

Formula:

Re = A0 / Af

Substitution:

Re = 5000 / 625

Result:

Re = 8

The extrusion process has an extrusion ratio of 8:1.

Applications

Aluminum extrusion

Copper extrusion

Polymer extrusion

Extrusion die design

Manufacturing process planning