Aluminium Extrusion - Tapered Section

[engineeringspread]

Tried searching google but struggled to find any information.

I am familiar with the standard aluminium extrusion process for constant section. I am wondering if there is a possibility to extrude a section lets say circular starting at 100mm diameter reducing to 75mm over an 8m length, maintaining a 5mm wall thickness.

I would be interested to know if this is possible and any references to the die design to achieve this.

 

[robyengIT]

with sailboat masts they do but I don't know the tolerances

 

[MintJulep]

Tapered aluminum tube is a thing.

It may begin as straight extruded tube.

Then tapered by other processes.

Constant wall thickness is probably hard.

 

[engineeringspread]

I have seen progressive forming of masts then welded, but never seen a tapered extrusion.

I have noticed reference to variable geometry dies so was curious if this is actually possible.

 

[drawoh]

engineeringspread,

A tapered tube sounds like a good application for welded sheet metal. The 5086 grade is fairly strong in the as-welded condition.

--
JHG

 

[3DDave]

https://forums.sailinganarchy.com/threads/new-mast-tapering-process.225632/

 

[kjoiner]

Hello,

I've seen impact extrusion used to make aluminum baseball bats but in this case the length is less than 1m vs the 8m length you're looking for.

Here's a video of the process:

https://www.youtube.com/watch?v=Aig6-q32Saw

Kyle

 

[engineeringspread]

I called a leading UK extruder and was informed this process is not one they are aware of, so my guess is this isn't possible.