# aerospace/aircraft/ultraamazing grade aluminum



## Handlobraesing (Mar 27, 2006)

These are words often used to describe the quality of aluminium used for flashlights, but what exactly does it mean when an aluminum alloy is "aerospace" grade as opposed to standard grade aluminum used for making ordinary products?


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## kf4zht (Mar 27, 2006)

My dad works for Kaiser Aluminum, and according to him the "areospace grade" is pretty broad, apparently they can use the aluminum for seat parts and push carts and call it "areospace", its more important to look at the type of aluminum and if you can, what company made/sold it.


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## drizzle (Mar 27, 2006)

A former tenant of mine made home-built helicopters. He was very particular about the numbers that identified specific grades of aluminum. He wanted different grades (alloys?) for the different parts that he was machining.


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## KDOG3 (Mar 27, 2006)

I'm building a gyroplane as we speak. The whole thing will be constructed out of 6061T6 aluminum. ALCOA makes alot of aluminum I use. I buy it from Aircraft Spruce and Specialty or Wicks Aircraft Supply. Good prices. Its amazing how cheap really good aluminum is.....


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## MadMag (Mar 27, 2006)

Aircraft aluminum normally means 7075....but sometimes this can be a loose term. 6061 or T6 is close. Anyway, 7075 is very high tensile strength compared to the lower series. Also, it will not get that nasty black on your hands. Also, you can tap threads in 7075 with good results. They now have a 800 series that is a little stronger. In my part of industry we used 7075 with almost as good a result as tool steel...but with light weight. Don't mean to say it will wear like tool steel...but still very strong.

Just to add. If you try to tap or thread lower series of alum. you get mush for threads....does not work at all.


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## TENMMIKE (Mar 27, 2006)

Generally 6061,7075,7050,7449(airbus), and 2024,are used , 
NOTE :the higher the number does not mean higher strength , ex. 2024 is stronger then 6061 they simply mean what the major alloying metal is.
If it will actually be used on a aircraft it means that a certification by a licenced or "approved" facility as to the % of alloying elements will accompany the material. ( known as a "cert") , if i can remember ill bring a cert in and scan and post it tomorrow....btw the "T" at the end,like T6 (7075 T6xxx) is the type of heat treat that has been performed
the letter "O"at the end means annealed and should be avoided unless your going to work it then heat treat it.


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## Data (Mar 27, 2006)

7075 T6 is aircraft grade. So much so that in times of war (like now) it is almost entirely taken up by those who make military parts. The price on it is also very high. I personally love the stuff, it cuts very nicely and stays shiny for a longer time than 6061 T6. 

However 6061 is not hard to cut tap or roll tap. It is a wonderful common high grade of aluminum. It is the aluminum used by machine shops everywhere. It mills and cuts perfectly. 7075 is just too expensive right now to be used in common stuff.


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## gadget_lover (Mar 27, 2006)

Would not true 'aircraft grade' be checked for voids, cracks and such before use in an aircraft? I seem to recall reading that aircraft grade parts are always fully inspected.

According to Machinery's handbook, the 2000 series and 7000 series are most often considered "aircraft" aluminum. The alloy 2024 is most widely used for parts and 7075 for airframes. The 6000 series anodizes better and is strong, but is not as strong as the the others.

Daniel


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## TENMMIKE (Mar 27, 2006)

parts are often sonic checked or dye pentrate checked as well a hardness checked after the machining and heat treating process ( it is not uncommon for a part to crack in the heat treating process), and yes there are many layers of inspection that follows all parts.


gadget_lover said:


> Would not true 'aircraft grade' be checked for voids, cracks and such before use in an aircraft? I seem to recall reading that aircraft grade parts are always fully inspected.
> 
> According to Machinery's handbook, the 2000 series and 7000 series are most often considered "aircraft" aluminum. The alloy 2024 is most widely used for parts and 7075 for airframes. The 6000 series anodizes better and is strong, but is not as strong as the the others.
> 
> Daniel


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## Data (Mar 27, 2006)

I used 2024 for the knobs and heads of my SPY light. It machines very nicely and is strong and stiff.


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## frisco (Mar 28, 2006)

All the above numbers are are pretty much "Aircraft" or "Aerospace" grade aluminum. It depends on the part. I have been around Race Car fabrication all my life and have a buddy that builds Top Fuel Dragsters. He taught me that different parts have different needs. In both race cars and aircraft you have to think: small, light, strong. 7075 has a very high tensile strength and it's great for parts that need it. Problem with 7075 is when it fails, it's so hard it breaks/cracks, it's almost brittle. Some parts are made with softer material because it's better for the part to bend or give a little before complete breakage actually occurs. Another thing to know about Aluminum... it actually has a grain to it... kinda like wood. So when making Aluminum parts you must be aware of grain direction for maximum strength. How does this pertain to Flashlights? I would think you want the material that machines the best and takes the anodizing the best.... were not talking about a part that takes allot of stress here.
Ever notice how some cheapy lights seem to be made of poor aluminum? Than have you ever wondered where all the Aluminum cans you recycle go?

frisco


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## NewBie (Mar 28, 2006)

7075 is not the only aerospace type of aluminum.

A wide variety is used in modern aircraft.


I know of alot of aerospace stuff that has 6061, 6063, and quite a few other grades of aluminum. Each has different properties, no one grade is suitable for everything on the aircraft...


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## Handlobraesing (Mar 28, 2006)

So, these high grade alloys can only be made from virgin aluminum?


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## gadget_lover (Mar 28, 2006)

Nah, Aluminum is easily purified and reused. It's apparently easy to remove the impurities, especially the organics since they burn right off.

Daniel


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## PEU (Mar 28, 2006)

Data said:


> I used 2024 for the knobs and heads of my SPY light. It machines very nicely and is strong and stiff.



I was told that the 20 series does not annodize well due to its high lead content.

Whats your experience? Did you tried scratching a spy with a xacto knife?

In trials I made with different alloys hard anodize threated (at least 30 microns), only 6061, 6262 and 7075 were perfectly inmune to a xacto, 2021 did not pass...


Pablo


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## gadget_lover (Mar 28, 2006)

In gerneral, the high Copper content in 20 series alloys prevent a goot coat using a standard HA process. There are processes (per a web search or two) that will HA a 2011 and 2024 alloy but it's not a home shop kind of process. You can do Type II on it but not HA.

I find the 2011 is nice for lights you will be leaving bare. It's harder and more scratch resistant than 6061. It polishes up real nice too. 6061's HA surface is more scratch resistant BUT it's a surface treatment that is somewhat brittle by comparison. Drop it on concrete and it will chip. 2011 also machines very nicely.

Daniel


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## Christoph (Apr 1, 2006)

Is 2024 easier to chrome plate ? thinking about some motorcycle parts

Chris


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## Data (Apr 1, 2006)

The question is, is it easier to copper plate? I would look for a chrome shop that specialize in auto restoration or a chrome shop that does production for the after market motorcycle parts industry. Then ask them if they have a preference for the grade of aluminum.


Dave


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