Grading Aluminun

[Kandace]

:confused: I've purchased some materials for my Gyrobee locally and some of the aluminum has no markings on in, I did order 6061-T6, but without markings on it how can you be sure what it is your getting?


Kandace :o

[scottessex]

I was going to bring up the same thing. I was told that the 2" squre does not carry markings because it is not "aircraft spec" as in "lockheed and Boeing don't use 2" tubing" but it is the same alloy. To me this sounds bogus. I mean they could sell you 6063 which is half the strength of 6061. Or they could sell you the same stuff you buy at Home Depot, you wouldn't know, untill your gyro falls apart in the air!
I too have the same problem, I have to rebuild my gyro but I need to be sure that the aluminum is the correct alloy. How do I know?? I am an aircraft mechanic, and I have never seen aircraft grade aluminum that was not marked.

I know that you can test for 2024 alloy by using an acid solution but I don't know of any tests for 6061. Somebody please help!

[Chuck Irby]

Kandace,

Like you, I would be very skeptical of the pieces without proper markings showing it to be 6061 T6. I don't ever recall getting any without the markings.

If I were in your position, I would pick up two pieces of scrap in known alloys, one soft and one 6061 T6. I then would use a file or a saw blade to determine the difference in the hardness. Another good way is to use a hammer and center punch to test the two known pieces for hardness. Then test the piece(s) in question the same way.

If there is any doubt at that point, I would have the supplier refund all expenses.

[Chuck Irby]

Sorry Scott, I didn't know you had posted until after I did.

[Brent_Brown]

I get the certification papers with it. But you have to ask for it when you order it.

[scottessex]

The only thing that bothers me is that the guys up front in the sales office can pull up paperwork in the office, but the lakeys in the warehouse can pull the aluminum from the wrong location and you would never know.

[Chuck Irby]

I totally agree with Scott. Papers don't mean didly. Brent, do you remember ever getting any 6061 T6 without the proper markings? I don't.

[Harry_S.]

I think, back in the old days, material was to be marked every 20 in. throughout it's length. Sheet stock was to also have 20 in. between lines of ID.

These dims. may be off a little, but it's been a while since I've been away from Mil Specs.

[Doug Riley]

I was in the business of selling gyro tubing for a dozen years or so. Some factoids:

(1) 2x2x.125 and 1x2x.125 are NOT stocked in the industry in 6061-T6. The standard alloy for these shapes is the infamous 6063-T5. This softer, weaker material is great for railings and supermarket door frames. It can't safely be substituted for 6061-T6 in any part that calls for the latter.

Because it's not a stock item, the chances that something you bought off the shelf is really 6061-T6 are rather low. The aluminum companies typically don't care and cannot be trusted if they supply you with unmarked material, paperwork or no. Been there, done that etc.

(2) Both the use of 6061-T6 and the marking are "extra cost" custom items. (So, by the way, is material that is guaranteed not to be all gouged up!) You only get these qualities if you specify them up front. You MIGHT run across some good material through a supplier who has some left over from another special order, but, again, don't take their word for it as regards unmarked material.

(3) For the small amount of material in a gyro, I'd strongly recommend that you buy from an aircraft supplier. Wicks, Aircraft Spruce and Starbee Gyros all have these materials. Dillsburg does, too, but theirs tends to be rather badly scratched and is sometimes unmarked. Scary.

(4) Even 2x2 6061-T6 isn't really "aircraft" material. It's still commercial grade, just better for our purposes. 2024-T3 and 7075-T6 are more typical aircraft alloys.

Doug Riley
(happily retired from the materials biz!)

[scottessex]

The reason I am concerned with this, I am in the process of rebuilding my gyro after breaking an axle. I tend to wonder if it was not 6063, instead of 6061 like I had paid for.........So I am going to be D@*n sure it is this time!
I bought the material from the company that supplys us, (major U.S. Airline) so I thought they would know what I needed. The 3/4" angle was marked, but the 2" was not.


Does Ernie, at rotor flight dynamics sell any material?? Just wondering, as I will be in Florida in a couple of weeks.

[Russell]

Even 2x2 6061-T6 isn't really "aircraft" material. It's still commercial grade, just better for our purposes. 2024-T3 and 7075-T6 are more typical aircraft alloys. I didn't know their was such a thing as aircraft aluminum?? I thought that aircraft was built using that grade and hardness of aluminum.?? Now don't everyone start jumping up and down on the key board. I had said the same thing to a very knowledgeable friend and he corrected me to this fact. I just want to hear it from the gyro people.
Russ :D

[scottessex]

I am not quite sure what you are asking, but yes there is such a thing as aircraft aluminum, mostly the 2024-T3 and 7075-T6, very much stronger than comercial grade, plus it has been hardened, it won't bend like the stuff you get at the hardware store. Plus most A/C alloy is Alclad, it has a coating of pure aluminum over it, the pure aluminum oxidizes, and protects the alloy. Look here for more info. http://www.aircraftspruce.com/catalog/mepages/aluminfo.php The bggest factor is 6061-T6 is TWICE as strong as 6063-t5. In other words, if you buy the wrong stuff it is only half as strong as it should be, and you could die.

[Russell]

Hi Scott, The entire page does not call any aluminum "Aircraft aluminum" but it does say Applications: Used in a wide variety of applications from aircraft components to home appliances, marine and transportation industry parts, heavy duty cooking utensils and equipment for bulk processing of food. Russ

[scottessex]

Well whatever, I would not use anything other than 2024-T3, 6061-T6, or 7075-T6, which is what aircraft are built from. with the exception of some -O soft aluminum that is formed and then heat treated to -3 or -6 spec, depending on the alloy.
So what I meant by "aircraft aluminum" was the 3 most common alloys used in production aircraft, and used in repair on certified aircraft.
Whatever you do don't buy from a hardware store and expect the part you make to have a very long fatigue life from standard comercial grade stuff.
I have done plenty of repairs to Lockheed, C-130, L-1011, McDonnel Douglas MD-11, MD88, Boeing, 737,757, and 767, and the repairs always called for one of these 3 types of alloy, unless it was a galley trim repair or some interior cosmetic.
that's all.

[Screw]

Screw-In

Ken Brock MFG will sell the materials.

Screw-Out

[GyroRon]

Ernie can sell you the tubing. He even has some 2x2 tubes with internal webbing to make it more like the two 1x2 pieces.

[scottessex]

Cool, I wondered if he could. Wicks aircraft sells it, but won't ship anything over 8 ft. unless it goes truck freight. Aircraft spuce doesn't sell it.
I'll just have to give Ernie a call here in the next week or so. I'll give him time to get back from Mentone.
Thanks Ron!

[Russell]

Most people dont know but Ernie is a dealer for just about anything to do with Gyro,s From Metals to radios and engines.
Russ :D

[Ralph]

StarBee Gyros stocks both 2x2 (3.16 wall) and 1x2 (1/8 wall). It is good stuff the the factory dye-mark labels are still on all pieces. The dealer/broker may come up with some song and dance, but if the metal doesn't carry the alloy label from the factory, I don't buy it!

Ralph

[joeheli]

I am just curios, or maybe I am stupid :o :D but I am plannig to buy all my gyro tubes too.
and I saw that the thickness of the tubes says .125. Is that decimal numbers or what? :confused:
I am plannig to get 1/8" thick.

[Caribean_gyro]

125 milesimas= 1/8 pulgadas.

[Chuck Irby]

Jose, In English .125 = 125/1000" or 1/8"; .25 = 250/1000" or 1/4"; .375 = 375/1000" or 3/8", etc..