Strength of aircraft grade versus 6061 aluminum?


Planning to use a short piece (2 or 3 inches) of 5/8" outer diameter
aluminum tubing. The wall thickness will be 1/16" to 1/8".
Pressing down on the center of the tube will be a maximum momentary
pressure of very roughly 300 pounds (a wild guess).
Is there any difference between 6061 aluminum and aircraft grade
aluminum for that purpose?
General ideas about the differences between the two would also be
appreciated.
Thanks.
FWIW:
With the aluminum tube end inner surface roughened, if I can get the
inner diameter correct so that the aluminum tube end can be glued
snugly around the motor gear, that should be straight and hold very
well. The aluminum tube might also provide good heat sinking when
spinning fast.
Reply to
John Doe
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?MatGUID=4f19a42be94546b686bbf43f79c51b7d Both yield and ultimate tensile for 7075-T6 are at least 80% higher than 6061-T6.
Reply to
Ned Simmons
Is "aircraft grade" something like "industrial strength" or "heavy duty"?
Reply to
Stupendous Man
Surgical Stainless Steel?
What you really want is "audiophile - quality Vulcanian billet".
--Winston
Reply to
Winston
The three word term "aircraft grade aluminum" in quotes produces almost one million results on the Yahoo search engine. The term is commonly used (and defined) at McMaster, a huge metal parts supply merchant on the web at
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and physically located in the United States.
Reply to
John Doe
Not exactly. Certain grades of aluminum were developed from need of the aircraft industry. They are, in general, very much stronger when heat treated (or aged) than other grades of aluminum. 7075 is likely the strongest (it rivals mild steel in tensile strength when aged to a T6, or T651 condition, with 2024-T351 being quite good as well.
Harold
Reply to
Harold and Susan Vordos
Alloys are not grades. The term "aircraft grade" is simply inept puffery in this context.
Reply to
Richard J Kinch
7075T? also considerably less ductal that 6061-T6...
If that matters in this application.
Reply to
cavelamb himself
"Aircraft Grade" sounds better than "beercan grade".
The poles for my extremely light Stephenson tent are 7001(?) aluminum tube, 5/8" OD, 0.015" wall. (Jack was once an aerospace engineer.) I picked the tent up at his house and he showed me how strong the poles are by placing a 16" piece on blocks and having me stand in the middle, barefoot. OTOH the alloy cracks easily and is 'notch sensitive'. I split the end of one of the sections by tying it down a little too tightly on my motorcycle with bungee cords. The tent still stands with one taped break but it loses some wind resistance. While I was there he got a call from someone camped on top of Mt Washington whose tent was surviving a 125 MPH wind.
As I understand it, 6061 is the strongest alloy that doesn't have corrosion, brittleness and joining issues requiring extra engineering analysis.
Jim Wilkins
Reply to
Jim Wilkins
I should have mentioned that they are very open-minded 'naturists' and the web site may not be entirely suitable for children.
Reply to
Jim Wilkins
It's thrown around pretty loosely these days, but the term originally referred to the aluminum-copper alloys developed in Germany around WWI, which were given the name Duralumin. They were similar to today's 2024. Then other precipitation-hardening grades were developed, and the term today usually refers to 2024, 7075, and maybe a couple of other grades in the 2000- and 7000 Series.
But it's become a marketing term, like "billet," so you can't count on it referring to a particular grade anymore.
-- Ed Huntress
Reply to
Ed Huntress
On Mon, 06 Oct 2008 23:58:07 -0700, the infamous Winston scrawled the following:
Right. One can't beat the oxygen-free, audiophile-quality, Vulcanian billets of aloonimum, can one?
Reply to
Larry Jaques
Besides price, yes that matters. I'm probably going to struggle just to get the fit right without grinding the motor gear, so being ductile is potentially important. I'm also looking at some sort of nylon/whatever thin tubular spacer if necessary to decrease the inner diameter of the aluminum tube.
But I'm curious about aircraft grade aluminum too. So far I picked up at least two different numbers (2024, 7075) designating aircraft grade aluminum, and the idea that metal can be hardened with aging (didn't know that one).
Thanks to the replies.
Reply to
John Doe
Look up precipitation hardening of aluminum. That's a more precise name for "age hardening." Some grades harden that way. Others don't.
-- Ed Huntress
Reply to
Ed Huntress
1. As you've found out, there are different "aircraft grade" aluminum alloys out there. Think about specific alloys, not "aircraft grade" vs. "landfill grade" (although I haven't seen any Al marketed as "landfill grade". I wonder why?).
2. Why not 5/8" rod, with an appropriate sized hole in one or both ends?
3. My intui-meter tells me that 300lb on a 1/8 wall 5/8" diameter 6061-T6 tube ought to be OK. Do you have reason to suspect otherwise?
3a. It makes a big difference how and how often this load will be applied -- with a sharp edge? Squishing the tube? Trying to rip the tube off of the shaft it's mounted to? What?
Reply to
Tim Wescott
Ed My son had a project where he built jet engine hangers for a new, more powerful C7 military transport jet engine. The billets for this project were 4" thick by 48" by 144". "The Kid" only knew it was a special military grade AL alloy. He brought home a pile of scrap from this job. Any way to guess what this stuff is and its properties? I've got a few hundred lbs.
Karl
Reply to
Karl Townsend
Ed,
The story of the development of precipitation hardening aluminum alloys is quite interesting.
Recalling from memory... One investigator was showing two visually identical strips of copper-bearing aluminum alloys to a colleague and asked him to bend them by hand. Although identical in size and alloy, one could be bent and one could not. The difference was the precipitation hardening.
The discussion turned to the % composition. Much of the early work was based on experiences with copper alloys such as brass and bronze, where the alloying constituent may be from say 5% to 40%. And aluminum bronze is an alloy of approx. 10% Al and 90% Cu, forming an exceedingly tough and abrasion metal.
The investigator stated that the copper content was less than 1% and closer between .25% and .5%. The colleague asked "why so little" and the reply: "In steel alloys you only have carbon content at typically less than 1% also. When I first read this tale in a book entitled "Metall" 40 or 50 years ago I was fascinated.
Wolfgang
Reply to
wfhabicher
In a word or two. Forget the "buzz words" and learn what the aloy numbers mean and USE them. ...lew...
Reply to
Lew Hartswick
In my signature, you see "rollerblades". Strictly speaking, that should be "in-line skates", but most people couldn't care less and "rollerblades" makes perfect sense to the vast majority of readers.
Reply to
John Doe
This skate looks like it would way upset the proper balance of the toes and ball of the foot over the leading edge of the skate?
Reply to
Richard J Kinch

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