skyguynca
Gold Member
- Joined
- Sep 23, 2004
- Messages
- 1,413
- 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?
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?