Bayonet union

The die is often provided with a bayonet union to secure it in such case the loose fit and the lacking protection against rotation give rise to objections. This type of securing the die is therefore not suitable for general application. 

The cross-section of the core of the thread has to take heavy tensile stresses both during extrusion and when pulling the mandrel out of the extruded tube. That is why bayonet unions between mandrel and holder are not used, because in such case the diameter of the head of the mandrel-holder would be too wide and the extrusion ram would be weakened too much. 

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