1. Cross-section size

The size of the section is measured by the profile external circle, and the larger the external circle, the greater the extrusion force required.

Extrusion ratio = extrusion cylinder area / profile cross-sectional area (ideal: 20-60))

The smaller and thinner the profile, the higher the extrusion ratio, and the greater the relative pressure on the mold, which is easy to cause metal fatigue and low extrusion speed.

2. Complexity of cross-sectional shapes

Cross-sectional shapes can be divided into three categories, namely solid profiles, semi-hollow profiles and hollow profiles.

In addition to the complexity of the section, consider its shape factor. The shape factor is the ratio of the sectional perimeter to the mass per unit of the profile (or the ratio of the perimeter to the cross-sectional area)

Hollow products increase in difficulty as the complexity of hollows and the number of hollows increase. Generally speaking, the more complex the hollow shape, the greater the difficulty of molding, the greater the number of hollow cores, the greater the difficulty of mold making, and the higher the cost.

3. Squeeze coefficient 

In order to make the extruded profile have a certain amount of deformation, and at the same time not to be difficult to squeeze, it is important to choose the extrusion coefficient reasonably. In general, the extrusion coefficient of pure aluminum can reach 300, alloy 6063 can reach 200, and duralumin can be selected between 20-60.

4. Profile wall thickness

The minimum wall thickness of a particular profile depends on the size of the external circle diameter of the profile, alloy composition and shape factors, etc., and the wall thickness is related to the difficulty of extrusion of the alloy.

5. Enclosing space area

The cross-sectional shape of the profile, where there are three parties surrounded, one side of the opening part, we call it the space area.

This space from the mold side is a cantilever beam, when the cantilever beam is thin and deep, the mold damage rate is large, even difficult to squeeze out, even if it can be squeezed out, it is difficult to squeeze out the qualified profile.