guardjim

I always see references to various gun parts being made from "aircraft aluminum". Is there a different formula for aircraft aluminum? Would it still be aluminum or would it become an alloy? Is it because it is milled from a billet instead of cast in a mold? If so, wouldn't it still be just aluminum since it's, well, aluminum?

one eye joe

Imho, it's a term that tells little--akin to the term "surgical steel" which is used in reference to knife blades......

dfariswheel

"Aircraft aluminum" is simply an alloy of aluminum.

The term aircraft aluminum is an advertising term. It sounds better then beer can aluminum, or hub cap aluminum.
There are many alloys of aluminum, many used in aircraft and in beer cans.

swshooter

I know that parts I cut for Boeing are T-6 aluminum and it is extremely brittle our pressbrake operators hate it.
God Bless,
Dan

one eye joe

Welcome to the forum, swshooter. "T-6 aluminum" is a term that actually defines a particular alloy of Aluminum, as opposed to the meaningless term, "aircraft aluminum". I'm sure that in the myriad of aluminum parts found in an aircraft, NOT all of them require the properties inherent in T-6......

Bob Reed

Hello Jim,

Most people are referring to 7075-T6 when they say aircraft aluminum, and 7075-T6 is good stuff. For example, Genuine COLT M16/M4/AR-15 Receiver Extensions (buffer tubes) are made from Hammer Forged 7075-T6 and COLT Upper & Lower Receivers are made from 7075-T6 as well.

Here's a site that you may find useful Aluminum Grades :: KEY to METALS

dfariswheel

I still like "space age aircraft aluminum".

The topper was Colt Firearms in the early 50's.
They were one of the first companies to make guns from aluminum.
The Colt Commander and Cobra were early aluminum framed guns.

Colt called their aluminum alloy "Coltalloy".

aryfrosty

Wasn't there a model called the Aircrewman"? Seems like I saw one in Bangkok long years ago. I think it had an aluminum cylinder also.

George M.

Thanks for the link Bob, I'm kind of into metals. George M.

dfariswheel

Yes, Colt did make the Aircrewman specifically and only, for the US Air force.
The Air Force also had S&W build the Model M-13 Aircrewman. Both guns had an aluminum frame and cylinder.
These were ordered by General Curtis Lemay to arm SAC crews. Lemay wanted the lightest possible .38 Special revolvers as crew armament.

Under testing, the aluminum cylinders failed to stand up to much shooting, so the guns were recalled and destroyed by the government.
Only about 25 Colt Aircrewman revolvers survived destruction and these are valuable collectors guns.

Silhouette

Straight for Wikipedia: Aluminium alloys are alloys in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for wrought products, for example rolled plate, foils and extrusions. Cast aluminium alloys yield cost effective products due to the low melting point, although they generally have lower tensile strengths than wrought alloys. The most important cast aluminium alloy system is Al-Si, where the high levels of silicon (4.0% to 13%) contribute to give good casting characteristics. Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required.[1]

Alloys composed mostly of the two lightweight metals aluminium and magnesium have been very important in aerospace manufacturing since somewhat before 1940. Aluminium-magnesium alloys are both lighter than other aluminium alloys and much less flammable than alloys that contain a very high percentage of magnesium.[citation needed]

Aluminium alloy surfaces will keep their apparent shine in a dry environment due to the formation of a clear, protective layer of aluminium oxide. In a wet environment, galvanic corrosion can occur when an aluminium alloy is placed in electrical contact with other metals with more negative corrosion potentials than aluminium.

Aluminium alloy compositions are registered with The Aluminum Association. Many organizations publish more specific standards for the manufacture of aluminium alloy, including the Society of Automotive Engineers standards organization, specifically its aerospace standards subgroups,[2] and ASTM International.

billt

As a machinist I can tell you from experience that 7075-T6 Aluminum is the toughest to cut. It is substantially tougher and harder on tooling than most of the other Aluminum alloys. In many regards it cuts more like free machining steel than it does Aluminum. It is also more expensive than most of the other Aluminum alloys.

Bob Reed

Hello Bill,

I'm a machinist too - and you're right about it, plus it doesn't rust overnite from handling like the low-grade steels do down here in this humid swamp!

Scottly

I am new, so I hope my contribution to this thread isn't scorned upon...

2011 is the most machinable of the commonly available aluminum alloys. Machining this alloy can produce excellent surface finishes on your product, and small, broken chips.

Weldability, strength, and anodizing response are all rated as average at best, and this alloy does not have a high degree of corrosion resistance.

2024 Aluminum
Copper is the main alloying ingredient in 2024. It is very strong compared to most aluminum alloys, and has average machinability, but the copper component of this alloy makes it susceptible to corrosion (many items in this alloy are produced with a clad surface to protect the underlying material.) In addition, 2024 is not considered to be weldable.

Finally, the fatigue resistance of 2024 make it a primary choice when the application is expected to be under stress or strain for prolonged periods. It is commonly used in aerospace applications.

5052 is the alloy most suited to forming operations, with good workability and higher strength than that of the 1100 or 3003 alloys that are commercially available.

5052 is not heat-treatable, but is stronger than most of the 5xxx series of alloys. It has very good corrosion resistance, and can be easily welded. 5052 is not a good choice for extensive machining operations, as it has only a fair machinability rating.

6061 Aluminum is, by most any measure, the most commonly used aluminum alloy. It is specified in most any application due to its strength, heat treatability, comparatively easy machining, and weldability. If that were not enough, it is also capable of being anodized, adding a layer of protection for finished parts.

The main alloy ingredients of 6061 aluminum are magnesium and silicon.

6063 is often called architectural aluminum for two reasons - first, it has a surface finish that is far smoother than the other commercially available alloys, and second, its strength is significantly less (roughly half the strength of 6061), making it suited for applications where strength is not the foremost consideration.

6063 is rated as "Good" for forming and cold working operations, "Excellent" for anodizing, and "Fair" for machining.

6101 is best suited for applications involving moderate strength and maximum electrical conductivity. It is similar to alloy 6063, but with minor chemistry changes which enhance electrical conductivity. Although slightly lower in conductivity than alloy 1350, it offers greater strength. Its most typical application is bus bar.

7075 is the other "aircraft grade" aluminum that is carried by OnlineMetals. Its principal alloying ingredients are zinc and copper, which make it one of the highest-strength aluminum alloys that are available. In fact, its typical strength in the T6 temper is higher than most mild steels.

7075 also has average-to-good ratings for machinability, corrosion resistance, and anodizing response. Like 2024, however, it is not considered to be weldable.

Bob Reed

Good info - Thanks for posting it.