Spars - Drawn seamless vs. Extruded

[Luked 71]

I was hoping to pick up some spar material locally today, but ran into this question. It looks like the original material in used in my Avid project is marked as ASTM-B-210 (Aluminum Alloy Drawn Seamless Tubes). I think most of the tubing available locally is extruded. Does anyone have any info on this. I was hoping to get my tubing today, but I'm kind of hesitating now.

Edit: Well, I found a place that has the drawn seamless, so I'm going to go with that. It's about 50% more. This might be something to keep in mind if you are buying locally instead of ordering from someone like Aircraft Spruce. Btw, ACS lists 2.5" x .065" @ $8.75/ft. The local place sells 12 ft pieces only, but the cost comes out to $6.25/ft.

Edited 14 Jan 2016 by Luked

[nlappos 413]

I did some research on the difference, and there is a significant difference. Drawn tubing is extruded tubing that is pulled a second time through the dies, so it is cold-worked which raises its strength and dimensional accuracy. I would stick to drawn ASTM tubing as called out.

[Luked 71]

Thanks nlappos. After some google searches that's the conclusion I was coming to. Good to have someone else confirm.

[EDMO 1078]

Luke,

To show the difference in prices, I just bought tubing locally for ailerons - The 1" x.125 wall 6061 drawn was almost $4.00 a foot, and the extruded was $1.45 a foot.  I bought the extruded.  Probably would have bought the DOM (Drawn on Mandrel) if I had been buying spar tubes.  Same goes for 4130 steel tubes.

EDMO

Edited 18 Jan 2016 by EDMO