Go Back   Maryland Shooters > Topics of Interest > Gunsmithing
Don't Have An Account? Register Here

Join MD Shooters

Reply
 
Thread Tools Display Modes
Old January 21st, 2019, 09:50 AM #11
MigraineMan's Avatar
MigraineMan MigraineMan is online now
Senior Member
 
Join Date: Jun 2011
Location: Frederick County
Posts: 9,727
MigraineMan MigraineMan is online now
Senior Member
MigraineMan's Avatar
 
Join Date: Jun 2011
Location: Frederick County
Posts: 9,727
6061 = spruce/pine/fir
7075 = red oak
7029 = white oak
MigraineMan is online now   Reply With Quote
Old January 21st, 2019, 12:10 PM #12
dmable44 dmable44 is offline
Junior Member
 
Join Date: Jul 2018
Posts: 67
dmable44 dmable44 is offline
Junior Member
 
Join Date: Jul 2018
Posts: 67
Quote:
Originally Posted by Pinecone View Post
T5/T6 DOES have meaning.

It has to do with the heat treating levels and has to do with ductility and brittleness.

Aircraft grade is a marketing term.

Aircraft use a number of alloys for different use. There is no real "aircraft grade." 2024T6 is 2024T6

There are some specific forms of shapes that are made for aircraft use. Most aircraft skins are 2014 Alclad. Alclad is a like a modern US coin. A sandwich. the bulk of the sheet is 2014, but each side has a thin layer of pure aluminum for corrosion resistance.

Well yes, everything has a meaning. However to 9/10 people it won’t make any difference for what they are using the firearm for.
dmable44 is offline   Reply With Quote
Old January 21st, 2019, 01:22 PM #13
Boxcab's Avatar
Boxcab Boxcab is online now
MSI EM
 
Join Date: Feb 2007
Location: AA County
Posts: 5,738
Boxcab Boxcab is online now
MSI EM
Boxcab's Avatar
 
Join Date: Feb 2007
Location: AA County
Posts: 5,738
Some basics...

Quote:
Heat-Treatable Alloys


Some alloys are strengthened by solution heat-treating and then quenching, or rapid cooling. Heat treating takes the solid, alloyed metal and heats it to a specific point. The alloy elements, called solute, are homogeneously distributed with the aluminum putting them in a solid solution. The metal is subsequently quenched, or rapidly cooled, which freezes the solute atoms in place. The solute atoms consequently combine into a finely distributed precipitate. This occurs at room temperature which is called natural aging or in a low temperature furnace operation which is called artificial aging.

2xxx Series

In the 2xxx series, copper is used as the principle alloying element and can be strengthened significantly through solution heat-treating. These alloys possess a good combination of high strength and toughness, but do not have the levels of atmospheric corrosion resistance as many other aluminum alloys. Therefore, these alloys are usually painted or clad for such exposures. They’re generally clad with a high-purity alloy or a 6xxx series alloy to greatly resist corrosion. Alloy 2024 perhaps the most widely known aircraft alloy.

6xxx Series

The 6xxx series are versatile, heat treatable, highly formable, weldable and have moderately high strength coupled with excellent corrosion resistance. Alloys in this series contain silicon and magnesium in order to form magnesium silicide within the alloy. Extrusion products from the 6xxx series are the first choice for architectural and structural applications. Alloy 6061 is the most widely used alloy in this series and is often used in truck and marine frames. Additionally, the iPhone 6 extrusion was made from 6xxx series alloy.

7xxx Series

Zinc is the primary alloying agent for this series, and when magnesium is added in a smaller amount, the result is a heat-treatable, very high strength alloy. Other elements such as copper and chromium may also be added in small quantities. The most commonly known alloys are 7050 and 7075, which are widely used in the aircraft industry. Apple®’s aluminum Watch, released in 2015, was made from a custom 7xxx series alloy.

Non Heat-Treatable Alloys

Non-heat treated alloys are strengthened through cold-working. Cold working occurs during rolling or forging methods and is the action of “working” the metal to make it stronger. For example, when rolling aluminum down to thinner gauges, it gets stronger. This is because cold working builds up dislocations and vacancies in the structure, which then inhibits the movement of atoms relative to each other. This increases the strength of the metal. Alloying elements like magnesium intensify this effect, resulting in even higher strength.

3xxx Series

Manganese is the major alloying element in this series, often with smaller amounts of magnesium added. However, only a limited percentage of manganese can be effectively added to aluminum. 3003 is a popular alloy for general purpose because it has moderate strength and good workability and may be used in applications such as heat exchangers and cooking utensils. Alloy 3004 and its modifications are used in the bodies of aluminum beverage cans.

4xxx Series

4xxx series alloys are combined with silicon, which can be added in sufficient quantities to lower the melting point of aluminum, without producing brittleness. Because of this, the 4xxx series produces excellent welding wire and brazing alloys where a lower melting point is required. Alloy 4043 is one of the most widely used filler alloys for welding 6xxx series alloys for structural and automotive applications.

5xxx Series

Magnesium is the primary alloying agent in the 5xxx series and is one of the most effective and widely used alloying elements for aluminum. Alloys in this series possess moderate to high strength characteristics, as well as good weldablility and resistance to corrosion in the marine environment. Because of this, aluminum-magnesium alloys are widely used in building and construction, storage tanks, pressure vessels and marine applications. Examples of common alloy applications include: 5052 in electronics, 5083 in marine applications, anodized 5005 sheet for architectural applications and 5182 makes the aluminum beverage can lid. The U.S. military’s Bradley Fighting Vehicle is made with 5083 and the 7xxx series aluminum.
https://www.aluminum.org/resources/i...num-alloys-101



.
__________________
Quote:
"I do find myself cursing the ghosts of the politicians and gun owners who let our 2nd Amendment rights degrade over the past century. Seven plus decades of being afraid to enthusiastically challenge any new ban against our gun rights has proven to be very foolish. Your rights will not preserve themselves; they must be pursued, secured and vigilantly maintained."
Boxcab is online now   Reply With Quote
Old January 21st, 2019, 01:31 PM #14
Boxcab's Avatar
Boxcab Boxcab is online now
MSI EM
 
Join Date: Feb 2007
Location: AA County
Posts: 5,738
Boxcab Boxcab is online now
MSI EM
Boxcab's Avatar
 
Join Date: Feb 2007
Location: AA County
Posts: 5,738
As for Aircraft use, just one page from my DAC Structures Design Manual...
It has lots of pages dealing with different kinds and forms of ALUM.

.
Attached Images
 
__________________
Quote:
"I do find myself cursing the ghosts of the politicians and gun owners who let our 2nd Amendment rights degrade over the past century. Seven plus decades of being afraid to enthusiastically challenge any new ban against our gun rights has proven to be very foolish. Your rights will not preserve themselves; they must be pursued, secured and vigilantly maintained."
Boxcab is online now   Reply With Quote
Old January 21st, 2019, 01:41 PM #15
ironpony's Avatar
ironpony ironpony is offline
@therange
 
Join Date: Jun 2013
Location: Crofton/Davidsonville
Posts: 5,222
ironpony ironpony is offline
@therange
ironpony's Avatar
 
Join Date: Jun 2013
Location: Crofton/Davidsonville
Posts: 5,222
Quote:
Originally Posted by MigraineMan View Post
6061 = spruce/pine/fir
7075 = red oak
7029 = white oak

Now that I can relate to ....
ironpony is offline   Reply With Quote
Old January 22nd, 2019, 12:54 AM #16
jrumann59's Avatar
jrumann59 jrumann59 is offline
DILLIGAF
 
Join Date: Feb 2011
Posts: 10,041
jrumann59 jrumann59 is offline
DILLIGAF
jrumann59's Avatar
 
Join Date: Feb 2011
Posts: 10,041
Quote:
Originally Posted by dmable44 View Post
Not a metallurgist but a welder. For 9/10 people here that aren’t dragging there ARs up and down Everest or through the Sahara, it doesn’t make a damn bit of difference. All this “aircraft grade” and “T6/T5” is just used as a marketing term to fool people into spending more money.
Basically you are saying most ARs are safe queens....
jrumann59 is offline   Reply With Quote
Old January 22nd, 2019, 12:26 PM #17
dmable44 dmable44 is offline
Junior Member
 
Join Date: Jul 2018
Posts: 67
dmable44 dmable44 is offline
Junior Member
 
Join Date: Jul 2018
Posts: 67
Quote:
Originally Posted by jrumann59 View Post
Basically you are saying most ARs are safe queens....
Yupp. The average person isn’t taking theirs out on a 2 week field ruck or “insert any other actual hard use scenario that these firearms were designed for”. Yes, I’m sure a few use and abuse but most are just taken to the range and back.
dmable44 is offline   Reply With Quote
Old January 22nd, 2019, 01:37 PM #18
Z_Man Z_Man is offline
Senior Member
 
Join Date: May 2014
Location: Harford County
Posts: 2,612
Z_Man Z_Man is offline
Senior Member
 
Join Date: May 2014
Location: Harford County
Posts: 2,612
well you can have drastic strength differences of 7075 depending on the Temper. the yield strength for 7075 without heat treat is ~21,000 psi while T6 is ~65,000 psi. for 6061 with no heat treat the yield strength is ~8000 psi, and 6061 with T6 heat treatment is roughly 35,000 psi of yield strength. yield strength is that point at which plastic deformation (permanent) begins. also, 6061 has MUCH better corrosion resistance to 7075, but its also cheaper which is why some discount rifles will use it over the 7075. yield strength isn't everything as far as wear reduction, surface prep, coatings, and anodizing will have a big impact on longevity of an individual rifle part. i would be more critical of a lower receiver being manufactured out of a sub mil-std part than an upper receiver, due to the function and stresses on each part. if the part is properly surface finished, and the rifle is lubricated correctly i don't see the upper receiver being the point of failure. but i am not an expert, and the threaded area the barrel is torqued to would be the area of concern.

the 7029 is going to be similar to 7075, but i cannot comment on its strength based on heat treatment. the material matters, but to most people it really won't. it all depends on cost savings and what you'll use the rifle for. an upper reciever is a relatively inexpensive piece of the rifle. last i checked retail price on a stripped mil-spec forged upper reciever is ~50 bucks. if you shop for sales $35. i don't know how much cheaper a 6061 or a 70xx material upper would be, as i don't know if I've ever seen them for sale retail.
Z_Man is offline   Reply With Quote
Old January 22nd, 2019, 02:26 PM #19
dontpanic's Avatar
dontpanic dontpanic is offline
Senior Member
 
Join Date: Jul 2013
Location: Timonium
Posts: 5,393
dontpanic dontpanic is offline
Senior Member
dontpanic's Avatar
 
Join Date: Jul 2013
Location: Timonium
Posts: 5,393
Quote:
Originally Posted by MigraineMan View Post
6061 = spruce/pine/fir
7075 = red oak
7029 = white oak
Not quite, because red oak SUCKS. Maybe 7075=ash
dontpanic is offline   Reply With Quote
Old January 22nd, 2019, 05:15 PM #20
Eddie Van's Avatar
Eddie Van Eddie Van is offline
Dude
 
Join Date: Feb 2011
Location: Hollywood Star Lanes
Posts: 580
Images: 3
Eddie Van Eddie Van is offline
Dude
Eddie Van's Avatar
 
Join Date: Feb 2011
Location: Hollywood Star Lanes
Posts: 580
Images: 3
Aircraft parts manufacturer and Materials Engineer here and can confirm Boxcab, Pinecone and Zman covered the subject well.

Will only add that 7029 is a high strength alloy approaching the properties of 7075 provided both are tempered (T5/T6/T7) to spec.

Cost-wise for raw material, 6061-T6 is cheaper than 7075-T7 and 7029-T5 is in the middle (if it can be sourced, which is difficult as it's not too popular compared to 7075 )
__________________
"One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision." - Bertrand Russell

"Do what you can, with what you have, where you are." - Theodore Roosevelt
Eddie Van is offline   Reply With Quote
Reply

  Home Page > Forum List > Topics of Interest > Gunsmithing


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:19 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
© 2019, Congregate Media, LP Privacy Policy Terms of Service