Looking for opinions from experienced builders and guru's, Chuck John Scott...?????

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
I sent this PM to a few people but I thought it better to open it up here and see what everyone thinks or their opinion on it.

I am a machinist and welder. I have built several gyros, two helicopters and quite a few airplanes from plans over the years. However I do not know it all or experienced it all.

I am looking for an opinion, not really an definitive answer. I know NO ONE wants to give a yes or no answer because in this day and age, some one will sue you for that.

That is why I am asking for your opinion, everyone is allowed to have an opinion and you can not be held responsible for that.

So here is what I am asking or putting forward for review

OK, Aircraft Spruce 6061T6 tubing is drawn thru a die, it meets ASTM B 210-04.

Now extruded 6061T6 tubing is under ASTM B221 and can be purchased at most metal yards.

Drawn has better external and internal dimension controls +/- .006 in diameter and+/- .003 in wall thickness

Extruded has good external dimension control but internals tend to be thicker in some spot than others but never more than +/- .005 wall and to +/- .006 in diameter but never below min diameter.

Now the alloy is the same, the temper is the same. The only differences I find are working pressures for fluid between the two ASTM's.

In an Air force paper MIL-DTL-25995C.pdf the air force requirements for Type 1 aluminum pipe in structural non pressure applications list both B210 and B221 ASTM qualification as the same acceptability.

3. REQUIREMENTS
3.1 Type I. Structural pipe for non-pressure applications shall be in accordance with ASTM B429, ASTM B483, ASTM B221, or ASTM B210.

So can you think of any safety reasons that the local purchased aluminum tubing that complies with ASTM B221 (printed on the side of the material by the manufacture) which has the same strength in tension and compression can not be used for airframe construction?
 

Smack

Re-member?
Joined
Nov 3, 2013
Messages
774
Location
Georgetown
Aircraft
Kitfox IV / F1 Rocket / Magni M-16 / Beech 18 / Aviomania G2sA-2
Total Flight Time
500+
I think drawn is structurally stronger (plastic deformation in the drawing process).
Here is a link that says such: https://getecna.com/what-is-the-dif...-aluminum-and-drawn-seamless-aluminum-tubing/
Probably (just sorta guessing) a drawn tube has less inclusions/micro-cracks than plain extruded.
I'd pay the extra $ for the better material; 'aircraft standards' have been created by the shed blood of aviators before us. ;)
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
I think drawn is structurally stronger (plastic deformation in the drawing process).
Here is a link that says such: https://getecna.com/what-is-the-dif...-aluminum-and-drawn-seamless-aluminum-tubing/
Probably (just sorta guessing) a drawn tube has less inclusions/micro-cracks than plain extruded.
I'd pay the extra $ for the better material; 'aircraft standards' have been created by the shed blood of aviators before us. ;)
Well that article say that cold drawn is stronger, but that is after it is extruded. Cold working always increases grain alignment and strength.

However that process of drawing depends on which ASTM it was manufactured under for the final strength properties.

Not arguing, but discussing the properties and from a safety aspect.

When you read the ASTM's for each extruded and drawn seamless there is very little difference in strength for compression or tensile. They only difference you see is in tensile strength at 6%, you can account for that with thicker wall. The ultimate yield is the same for 6061T6 produced under both ASTM's.

Also you refer to "aircraft grade". I have both ASTM's and no where in either one is that phrase or standard used. In fact after not only working on helicopters and airplanes for both the military and civilian world, 6061T6 and 2024T3 and 7075T4 are all considered aircraft grades with not a single reference to the ASTM that applies, for each one of these types of aluminum have 3 to 5 different ASTM's that can apply singularly or multiply by manufacture process.

As an example from B210 here is a reference for 6061T6 and it shows how this process meets two standards
1617482340685.png

Aircraft spruce shows the B210 chart for 6061T6

1617482885192.png

Here is one from B221 still talking about 6061T6

1617482418185.png


As you can see B210 has an elongation of 4-10 % and 8% for B221 for a difference of 4% to 2%
B210 has a Tensile of 42 ksi and B221 of 38 ksi
Ultimate Yield is 35 ksi and B221 is 35 ksi

So it is stronger is a few areas and weaker in others as it applies for both.
I think the only real difference would be in QC for micro inclusions. Not every inch of each piece is checked for that under B210, only batch samples.

Also here is the complete military reference for aluminum tube purchase DOD guide. As you can see it considers both ASTM's B210 and B221 to be equal under material for non-pressurized fluid pipe but used as structural members.

REQUIREMENTS
Type I. Structural pipe for non-pressure applications shall be in accordance with ASTM B429,
ASTM B483, ASTM B221, or ASTM B210.
Type II. Seamless pipe for pressure applications shall be in accordance with ASTM B241.


The full document is attached. So since it lists 4 different ASTM's including B210 that would mean that any manufactured aluminum pipe for a structural application that is non-pressured would be acceptable if it meets any of these ASTM's. You are calling ASTM B210 "aircraft grade" so these others would also fit that definition too?

Now with the ASTM comparable, which is the better material since the material spec is still and must still meet the 6061T6 chemical properties and structural limits of the classification?

I have put this to several engineers and they say use either just account for the 6% difference by using 6% thicker wall or in diameter.
 

Attachments

  • MIL-DTL-25995C.pdf
    85.5 KB · Views: 2

Martin W.

Active Member
Joined
May 10, 2020
Messages
330
Location
Winnipeg
SkyGuynca ... my comment has absolutely nothing to do with your question ... but folks may still find it interesting. I know I sure did.

I built a lot of things for a lot of years , go-carts , dune buggies , shelves and racks , fold out stands , metal ladders , overhead canopies , etc etc.

Normal people used 1 inch mild steel square tubing , cheap and easy to weld ...... but not me .... I preferred to go to the electric supply store and buy EMT electrical conduit tubing .... light weight , and does not rust , and seemed strong to me. And comes in sizes from half inch up to 6 inch

And because I am not a professional welder I would use brass rod and torch and braze the joints together ... low heat , brass swims around everywhere inside and outside the joint for good adhesion , then build up some extra brass material for strength .... in many ways brazing is more of an adhesive process than a true weld.

Took some ridicule of course , which I didnt mind , so one day we did a red-neck test ... joined two pieces with the proper steel welding rod method .... and one with my brass ... attached them in tandem with chains on the ends and used two pickup trucks for the pull to see which one broke first.

Both were actually very strong , trucks were spinning and skidding so we had to do a yank and jerk to make it break .... the brass joint survived and the steel one broke . I won a case of beer for that.

Jump ahead to last year ... a curious engineer did some research on EMT electrical tubing ... code requires it to meet some high standards , and for all practical purposes it is like 4130 aircraft tubing but with a galvanized coating to prevent corrosion. I will post the link if I can find it.

In summary my buddies should have bought me two cases of beer !!!!!!!!!!!!!!! haaaaaaaaaaa
 
Last edited:

MilesW

Junior Member
Joined
Jun 30, 2012
Messages
76
Location
Western Australia
Aircraft
Sportcopter M912
Total Flight Time
1400+ Gyro
So can you think of any safety reasons that the local purchased aluminum tubing that complies with ASTM B221 (printed on the side of the material by the manufacture) which has the same strength in tension and compression can not be used for airframe construction?

The chemistry and mechanicals for the base material may be the same but the construction is not.
Extruded hollow sections are not actually seamless. The ingot is split around the die mandrel and effectively welded back together under extreme pressure in the die. There is more than one "welded" seam.
I would hazard a guess that a large amount of it has found its way into airframes over the years.


Miles
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
Sorry Miles but that is incorrect. It is a hollow ingot that is pressed thru the die. That is why it is a seamless extrusion to meet B221 ASTM.

What you are referring to is a seamed tube.
From Smack's link above it explains the two types seamed and seamless, we are only interested in seamless

Extruded Aluminum Tubing​

There are two types of aluminum tubing created by the extrusion process. One type splits the aluminum tube as it is forced through the die, and needs to be sealed back together using a process such as welding for example. Because this tubing creates a seam, it is not as strong as the second type of extruded aluminum tubing: seamless extruded aluminum tubing. Seamless extruded aluminum tubing is created by pushing a hollow billet through a die. This creates a stronger aluminum tube that can be used for pressurized gases and liquids.
 

MilesW

Junior Member
Joined
Jun 30, 2012
Messages
76
Location
Western Australia
Aircraft
Sportcopter M912
Total Flight Time
1400+ Gyro
Sorry Miles but that is incorrect. It is a hollow ingot that is pressed thru the die. That is why it is a seamless extrusion to meet B221 ASTM.

What you are referring to is a seamed tube.
From Smack's link above it explains the two types seamed and seamless, we are only interested in seamless

Extruded Aluminum Tubing​

There are two types of aluminum tubing created by the extrusion process. One type splits the aluminum tube as it is forced through the die, and needs to be sealed back together using a process such as welding for example. Because this tubing creates a seam, it is not as strong as the second type of extruded aluminum tubing: seamless extruded aluminum tubing. Seamless extruded aluminum tubing is created by pushing a hollow billet through a die. This creates a stronger aluminum tube that can be used for pressurized gases and liquids.

I think you will find B221 is seamed and B241 is seamless
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
IF you read B221 (not just its title) you will see B221 is for structural seamless tubing that is non-pressurized. This one has to meet specific tensile and shear and elongation standards for structural applications.

If you read B241 (not just its title) you will see B241 is for non-structural seamless pressurized tubing. This one has to meet the specific standards for pressurized tubing to carry air and or liquids at a specific temperature range with very specific bursting limits.

Two entirely different tubing specifications. That is why in the previously attached document for the DOD specifically the Air Force Mil spec lists B210 and B221 as acceptable seamless structural tubing interchangeably.

I will attach it again, please read it this time. It explains the difference.
 

Attachments

  • MIL-DTL-25995C.pdf
    85.5 KB · Views: 0

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
OK, now because I do read, because I really want to know and learn. (That is why I actually save all posts by Don, Chuck, Scott, John and a few others) is because their information is REAL, not hear/say or rumor.

So I continued research and reading long past posting this thread. Now on the ASTM Standardization Committee, specifically The Aerospace Overview ( here is the link https://www.astm.org/industry/aerospace-overview.html ) I found some very interesting and very very enlightening information. Now I know a few people are going to say the items that I copied and pasted below are fake, that is why the link is above. You will see that in the aircraft standard ASTM B221 is used and there is no mention what so ever of the ASTM B210 that most people quote as "Aircraft Grade".

Funny huh? So this truly answers the question with no ambiguity at all. Please read.

Aerospace Overview

Keeping Aircraft Safe


Helping ensure aircraft are safe in the sky and on the ground, addressing some of the smallest parts of a private plane to the largest concerns of international airlines, a number of ASTM International committees develop standards critical to aircraft construction, parts manufacturing, maintenance and aviation fuel.

ASTM standards provide guidance for aircraft manufacturers as they design and build aircraft and for the manufacturers’ vendors as they develop the components necessary for a broad range of aircraft. Other ASTM standards cover various types of fuels, pavements and many more topics.

Those standards and test methods also address the directives of U.S. government organizations such as the Federal Aviation Administration (FAA) for the more than 19,000 airports, heliports and other landing facilities in the United States, and for other governing bodies and administrations around the globe.

ASTM committees and subcommittees involved in aviation standards include international members who develop standards that are used around the world. They include representatives from government offices, major airplane manufacturers and smaller firms, academia and vendors dealing with products related to all areas of flight.

As aviation-related committees and subcommittees continue to evolve, their standards address virtually every concern related to the field, from bearings to renewable fuels, from wiring to pavements.

The following pages briefly profile major ASTM International committees and subcommittees that have been instrumental in ensuring safety in all realms of aviation – and therefore safe flights and safe passengers – for more than 70 years.

These ASTM International committees and subcommittees have been instrumental in ensuring safety in all realms of aviation – and therefore safe flights and safe passengers – for more than 70 years.

Building the Aircraft

B07 Aluminum and Light Metals


Committee B07 on Light Metals and Alloys develops standards related to aluminum and magnesium and their alloys in cast and wrought mill product form as well as fabricated culvert materials, their structural design and installation.

B07’s collection of standards mainly includes test methods that are used throughout the aerospace industry for both quality assurance and design purposes. Properties measured in accordance with these test methods are used to determine design allowable limits that are published in “Metallic Materials Properties Development and Standardization,” which is used by the aerospace industry to satisfy design requirements from FAA, the U.S. Department of Defense and NASA.

B07 subcommittees have jurisdiction over 80+ standards that address the effective industrialization of light metals and their alloys, primarily with respect to aluminum and magnesium. Those standards cover topics such as aluminum for use in iron and steel manufacture; aluminum and aluminum-alloy sheet and plate; and aluminum-alloy extruded bars, rod, tube, pipe, structural profiles and profiles for electrical purposes.

Technical subcommittees in Committee B07 include:

  • B07.01 on Aluminum Alloy Ingots and Castings,
  • B07.03 on Aluminum Alloy Wrought Products,
  • B07.04 on Magnesium Alloy Cast and Wrought Products,
  • B07.05 on Testing,
  • B07.08 on Corrugated Aluminum Pipe and Corrugated Aluminum Structural Plate, and
  • B07.09 on US TAG National Committee for ISO/TC 79 on Light Metals and Alloys.
Important B07 Standards

  • Specification for aluminum and aluminum-alloy extruded bars, rods, wire, profiles and tubes (B221), which covers extruded bars, rods, wires, profiles and tubes made from aluminum and aluminum alloys;
  • Specification for aluminum and aluminum-alloy sheet and plate (B209), which covers aluminum and aluminum-alloy flat sheet, coiled sheet and plate in particular alloys and tempers;
  • Test methods for tension testing wrought and cast aluminum- and magnesium-alloy products (B557), which cover the tension testing of wrought and cast aluminum- and magnesium-alloy products, excepting aluminum foil;
  • Practice for linear-elastic plane-strain fracture toughness testing of aluminum alloys (B645), applicable to the fracture toughness testing of all aluminum alloys, tempers and products, especially in cases where the tests are being made to establish whether or not individual lots meet the requirements of specifications and should be released to customers;
  • Practice for fracture toughness testing of aluminum alloys (B646), which provides uniform test procedures for the industry, pointing out which current standards are utilized in specific cases and providing guidelines where no standards exist;
  • Test method for tear testing of aluminum alloy products (B871), which covers the static tear test of aluminum alloy products using specimens that are 0.040 inch (1 mm) to 0.250 inch (6.35 mm) thick and is applicable to aluminum alloy products having a minimum thickness of 0.040 inch (1 mm); and
  • Test method for shear testing of aluminum alloys (B769), which covers double-shear testing of wrought and cast aluminum products to determine shear ultimate strengths.
 

MilesW

Junior Member
Joined
Jun 30, 2012
Messages
76
Location
Western Australia
Aircraft
Sportcopter M912
Total Flight Time
1400+ Gyro
OK, now because I do read, because I really want to know and learn. (That is why I actually save all posts by Don, Chuck, Scott, John and a few others) is because their information is REAL, not hear/say or rumor.

So I continued research and reading long past posting this thread. Now on the ASTM Standardization Committee, specifically The Aerospace Overview ( here is the link https://www.astm.org/industry/aerospace-overview.html ) I found some very interesting and very very enlightening information. Now I know a few people are going to say the items that I copied and pasted below are fake, that is why the link is above. You will see that in the aircraft standard ASTM B221 is used and there is no mention what so ever of the ASTM B210 that most people quote as "Aircraft Grade".

Funny huh? So this truly answers the question with no ambiguity at all. Please read.

Aerospace Overview

Keeping Aircraft Safe


Helping ensure aircraft are safe in the sky and on the ground, addressing some of the smallest parts of a private plane to the largest concerns of international airlines, a number of ASTM International committees develop standards critical to aircraft construction, parts manufacturing, maintenance and aviation fuel.

ASTM standards provide guidance for aircraft manufacturers as they design and build aircraft and for the manufacturers’ vendors as they develop the components necessary for a broad range of aircraft. Other ASTM standards cover various types of fuels, pavements and many more topics.

Those standards and test methods also address the directives of U.S. government organizations such as the Federal Aviation Administration (FAA) for the more than 19,000 airports, heliports and other landing facilities in the United States, and for other governing bodies and administrations around the globe.

ASTM committees and subcommittees involved in aviation standards include international members who develop standards that are used around the world. They include representatives from government offices, major airplane manufacturers and smaller firms, academia and vendors dealing with products related to all areas of flight.

As aviation-related committees and subcommittees continue to evolve, their standards address virtually every concern related to the field, from bearings to renewable fuels, from wiring to pavements.

The following pages briefly profile major ASTM International committees and subcommittees that have been instrumental in ensuring safety in all realms of aviation – and therefore safe flights and safe passengers – for more than 70 years.

These ASTM International committees and subcommittees have been instrumental in ensuring safety in all realms of aviation – and therefore safe flights and safe passengers – for more than 70 years.

Building the Aircraft

B07 Aluminum and Light Metals


Committee B07 on Light Metals and Alloys develops standards related to aluminum and magnesium and their alloys in cast and wrought mill product form as well as fabricated culvert materials, their structural design and installation.

B07’s collection of standards mainly includes test methods that are used throughout the aerospace industry for both quality assurance and design purposes. Properties measured in accordance with these test methods are used to determine design allowable limits that are published in “Metallic Materials Properties Development and Standardization,” which is used by the aerospace industry to satisfy design requirements from FAA, the U.S. Department of Defense and NASA.

B07 subcommittees have jurisdiction over 80+ standards that address the effective industrialization of light metals and their alloys, primarily with respect to aluminum and magnesium. Those standards cover topics such as aluminum for use in iron and steel manufacture; aluminum and aluminum-alloy sheet and plate; and aluminum-alloy extruded bars, rod, tube, pipe, structural profiles and profiles for electrical purposes.

Technical subcommittees in Committee B07 include:

  • B07.01 on Aluminum Alloy Ingots and Castings,
  • B07.03 on Aluminum Alloy Wrought Products,
  • B07.04 on Magnesium Alloy Cast and Wrought Products,
  • B07.05 on Testing,
  • B07.08 on Corrugated Aluminum Pipe and Corrugated Aluminum Structural Plate, and
  • B07.09 on US TAG National Committee for ISO/TC 79 on Light Metals and Alloys.
Important B07 Standards

  • Specification for aluminum and aluminum-alloy extruded bars, rods, wire, profiles and tubes (B221), which covers extruded bars, rods, wires, profiles and tubes made from aluminum and aluminum alloys;
  • Specification for aluminum and aluminum-alloy sheet and plate (B209), which covers aluminum and aluminum-alloy flat sheet, coiled sheet and plate in particular alloys and tempers;
  • Test methods for tension testing wrought and cast aluminum- and magnesium-alloy products (B557), which cover the tension testing of wrought and cast aluminum- and magnesium-alloy products, excepting aluminum foil;
  • Practice for linear-elastic plane-strain fracture toughness testing of aluminum alloys (B645), applicable to the fracture toughness testing of all aluminum alloys, tempers and products, especially in cases where the tests are being made to establish whether or not individual lots meet the requirements of specifications and should be released to customers;
  • Practice for fracture toughness testing of aluminum alloys (B646), which provides uniform test procedures for the industry, pointing out which current standards are utilized in specific cases and providing guidelines where no standards exist;
  • Test method for tear testing of aluminum alloy products (B871), which covers the static tear test of aluminum alloy products using specimens that are 0.040 inch (1 mm) to 0.250 inch (6.35 mm) thick and is applicable to aluminum alloy products having a minimum thickness of 0.040 inch (1 mm); and
  • Test method for shear testing of aluminum alloys (B769), which covers double-shear testing of wrought and cast aluminum products to determine shear ultimate strengths.
 

MilesW

Junior Member
Joined
Jun 30, 2012
Messages
76
Location
Western Australia
Aircraft
Sportcopter M912
Total Flight Time
1400+ Gyro
Sorry, but you are still wrong. Since you want to learn, I suggest you contact a manufacturer, or since you also seem fond of google, try " B221 porthole".

I am not a guru, but I used to do this for a living.
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
So on the ASTM website, the people who set the standard, on the B07 committee who actually set the standard, when they print this:

Building the Aircraft

B07 Aluminum and Light Metals


Committee B07 on Light Metals and Alloys develops standards related to aluminum and magnesium and their alloys in cast and wrought mill product form as well as fabricated culvert materials, their structural design and installation.

B07’s collection of standards mainly includes test methods that are used throughout the aerospace industry for both quality assurance and design purposes. Properties measured in accordance with these test methods are used to determine design allowable limits that are published in “Metallic Materials Properties Development and Standardization,” which is used by the aerospace industry to satisfy design requirements from FAA, the U.S. Department of Defense and NASA.

B07 subcommittees have jurisdiction over 80+ standards that address the effective industrialization of light metals and their alloys, primarily with respect to aluminum and magnesium. Those standards cover topics such as aluminum for use in iron and steel manufacture; aluminum and aluminum-alloy sheet and plate; and aluminum-alloy extruded bars, rod, tube, pipe, structural profiles and profiles for electrical purposes.

Technical subcommittees in Committee B07 include:



  • B07.01 on Aluminum Alloy Ingots and Castings,
  • B07.03 on Aluminum Alloy Wrought Products,
  • B07.04 on Magnesium Alloy Cast and Wrought Products,
  • B07.05 on Testing,
  • B07.08 on Corrugated Aluminum Pipe and Corrugated Aluminum Structural Plate, and
  • B07.09 on US TAG National Committee for ISO/TC 79 on Light Metals and Alloys.
Important B07 Standards


  • Specification for aluminum and aluminum-alloy extruded bars, rods, wire, profiles and tubes (B221), which covers extruded bars, rods, wires, profiles and tubes made from aluminum and aluminum alloys;

You are saying that it is not truthful, that the B07 committee and the ASTM society are lying to people on their website. So where it directly says

B07’s collection of standards mainly includes test methods that are used throughout the aerospace industry for both quality assurance and design purposes. Properties measured in accordance with these test methods are used to determine design allowable limits that are published in “Metallic Materials Properties Development and Standardization,” which is used by the aerospace industry to satisfy design requirements from FAA, the U.S. Department of Defense and NASA.


Is also lying to the public too?


I am glad you did it for a living but this is exactly what it says on their website at ASTM. IT clearly says that the B07 committee sets the standards for materials for the FAA, Aircraft Manufactures Materials and under that it says that the B221 is the specification for structural materials and that is the subheading for the B07 committee.


So now are you going to say I can't read?

You make comments but you show no proof.
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
Sorry, but you are still wrong. Since you want to learn, I suggest you contact a manufacturer, or since you also seem fond of google, try " B221 porthole".

I am not a guru, but I used to do this for a living.
You are funny, this is directly from the ASTM website, remember I put the link in my comments. Oh wait again you did not read it.
There is no Google link in my comments, so you obviously decided to make up that comment on your own. Can I ask why?

Also why when I post the link to ASTM, to the B07 committee the group that deals with AIRCRAFT ASTM's, you still say this it is not true?

Why are you accusing me of making this up?

If you did this for a living, please post your proof.
 

skyguynca

Gold Member
Joined
Sep 23, 2004
Messages
1,390
Location
Acampo, CA
Aircraft
depends on what I have sold recently
Total Flight Time
5000+
Sorry, but you are still wrong. Since you want to learn, I suggest you contact a manufacturer, or since you also seem fond of google, try " B221 porthole".

I am not a guru, but I used to do this for a living.
You also disregard and failed to mention the DOD AirForce mil spec document that also states that ASTM B221 is for structural non - pressurized aluminum tubing.

So you think that is a fake document too?

Also not from google, from the DOD directly, Materials Management branch.

So why the google comment?
 
Last edited:
Top