1. A 25 to 30% reduction in load compared with direct extrusion.
2. The resultant higher extrusion load available can be used either to Extrude smaller cress sections or to decrease the billet temperatures, permitting the use of higher speeds.
3. The extrusion pressure is not a function of the billet length, because there is no relative displacement of the billet center relative to the peripheral region. The billet length is therefore not limited by the load required for this displacement but only by the length and stability of the hollow stem needed for a given
4. No heat is produced by friction between the billet and the Container, and consequently no temperature increase rs at the billet surface towards the end of extrusion, as is typical in the direct extrusion of aluminum alloys. Therefore, there is less tendency for the surfaces and edges to crack in the indirect process and significantly higher extrusion speeds can be used.
5. The service life of the tooling is increased, especially that of the inner liner, because of the almost total absence of friction. There is a more uniform deformation of the complete billet cross section with no tendency to from an extrusion defect or a coarse-grained peripheral zone.
6. Impurities on the billet surface do not finish up inside the Extrusion --- there is no metal turbulence in the container --- but can be found on the surface of the product.
7. No defect at the end of extrusion, as is typical in the direct Extrusion of brass.