extrusion process

[rancherman]

I think it was Denis who posted a reply a while back, about the difference in extrusions of square tubing..
One way has the inner profile 'die' being supported with wings, which actually separates the billet as it's pressed.. the heat and compressive forces essentially welds the corners back together. 'essentially'.

The other way, is the forming die is pressed in from the rear of the billet, and supported from the rear. No separation of material.

So, is there a designation for these different processes?

 

[Gyro Technic]

Yes,
Designated as "Seamless" or "Porthole"
Seamless is just that.
A porthole die requires the material to flow around the webs and then weld itself back together.
Denis