Specs. for aluminum air cylinder?

[Peep]

Aloha,

Have some 2024-T3, in 1.25" X 0.095" X 1.06". Would this be safe to machine into air cylinder for a Hatsan AT44 PA?

Mahalo for the replies.

 

[dizzums]

no idea .. i do know a couple of factors that may apply such as some grades have seams and some are seamless, and also anodizing likely adds strength .. personally id think i was probably fabricating a pipe bomb waiting to go off screwing around like that lol ...

 

[kayaker]

This is the wrong place for that advice, talk too a engineer. Better yet buy a lighter and better gun you'll be happier.

 

[thomasair]

It’s not even close. Google Barlows Formula calculator and look up the yield pressure of the alloy. Rule of thumb is yield must be 3x working pressure. That does not account for the end plugs, though.

The short answer is NO.

Mike 

 

[Peep]

Thanks Mike.

 

[PikeP]

2024-T3 tensile strength = 60-70,000 PSI or 480 MPA



Barlow formula is as follows

Working pressure = 2*(tensile strength * wall thickness / (tube OD * safety factor))

2*(70,000*.095/(1.25*3)) = 3500 psi

2*(60,000*.095/(1.25*3)) = 3000 psi



2*(70,000*.095/(1.25)) = 10,640 burst pressure

2*(60,000*.095/(1.25)) = 9,120 burst pressure

That gives you a working pressure of 3500 psi. on the high end, and 3000 psi on the low end...stick in the middle to be safe, or use 70k max for that material provided its data sheet lines up with my #'s...

 

[Peep]

Thanks PikeP. In my feeble bird brain it seems that 3250 psi is safe to use?

 

[thomasair]

Know the difference between ultimate tensile and yield tensile.

Mike 

 

[thomasair]

In actuality….there is no way to predict if your tube will be reasonably safe since you don’t provide a lot of other information that is extremely relevant. End cap design is a big deal. Usually internal threaded tubes with inboard orings will blow the end caps off at the root of the first thread long before the tube will burst. 

I’d suggest getting someone involved that can take all of your design parameters into consideration to determine safety if you are not equipped to do so yourself.

Mike 

 

[PikeP]

Thanks PikeP. In my feeble bird brain it seems that 3250 psi is safe to use?

Yes, provided you plug the ends correctly, that requires additional calculations, but if copying OEM or Marauder style, you'll be fine at that PSI.

 

[Peep]

If I have this cylinder made, the stock fittings would be used. Machinist will copy the threads, relief, o-ring etc. Thank you PikeP.