Hi do you have a tip how to expand a stainless steel pipe

[Marc Moreau]

Hi do you have a tip how to expand a stainless steel pipe from .875 to .940 with out removing material ? this bar is for my ULM pendular this is the bar you hold for driving .
Could I heat it red and push a steel round rod 15/16 with an hammer ? Thank You

 

[phaxtris]

why are you trying to expand it ? a sleeve on the outside would be easier and probably safer, if you can manage to expand it you will loose significant wall thickness

or a new pipe, you dont want the yoke to rip off mid flight

 

[whydontu]

Wall thickness? Grade of stainless?

 

[Susquatch]

You can buy or make tube expanders. They are commonly used for muffler tail pipes.

Here is an example.

Powerbuilt 940378 Medium Tailpipe Expander Set https://a.co/d/gfqOOOO

Maybe you can make one.

They are less and less effective as the tube wall gets thicker.

 

[Marc Moreau]

Wall thickness? Grade of stainless?

.065 The grade ???

 

[Marc Moreau]

why are you trying to expand it ? a sleeve on the outside would be easier and probably safer, if you can manage to expand it you will loose significant wall thickness

or a new pipe, you dont want the yoke to rip off mid flight

I try to not weld on those thing aviation and welding are not recommanded. For a new pipe they don't make this size.

 

[Marc Moreau]

You can buy or make tube expanders. They are commonly used for muffler tail pipes.

Here is an example.

Powerbuilt 940378 Medium Tailpipe Expander Set https://a.co/d/gfqOOOO

Maybe you can make one.

They are less and less effective as the tube wall gets thicker.

I try to find one but this is very small I didn't find one.

 

[phaxtris]

I try to not weld on those thing aviation and welding are not recommanded. For a new pipe they don't make this size.

you might end up with a pipe that is very thin after you expand it, you are going from a 2.74" circumference to a 2.95" circumference, that .200 has to come from somewhere, and its going to be the wall

 

[Marc Moreau]

you might end up with a pipe that is very thin after you expand it, you are going from a 2.74" circumference to a 2.95" circumference, that .200 has to come from somewhere, and its going to be the wall

No the pipe is .875 and need to expend to .940 this is only .065 removing this metal with a reamer will be scare me .

 

[Marc Moreau]

No the pipe is .875 and need to expend to .940 this is only .065 removing this metal with a reamer will be scare me .

The only thing make me scare if the stainless will crack after ?

 

[140mower]

Just thinking out loud here, can you get your hands on one of the bigger ones and scale it down and make your own? ........ I couldn't find one either

 

[Marc Moreau]

Just thinking out loud here, can you get your hands on one of the bigger ones and scale it down and make your own? ........ I couldn't find one either

Yes if I can find one who fit good over I will weld it but I have to cut side by side and remove some material and weld it again to have no gap between .

 

[Susquatch]

No the pipe is .875 and need to expend to .940 this is only .065 removing this metal with a reamer will be scare me .

That is indeed pretty small. You need an Expander that will go from 7/8 to 1". The smallest I have is about 2". I'll look at it tomorrow to see if a smaller one could be made from it.

I've also seen copper pipe expanders in that size range. But I'm not sure how well they would work on stainless. I'm thinking you might need to make something.

In the meantime, here is another type. That works with a hydraulic tool. You would have to adapt it to work manually.

uxcell 7/8" Hydraulic Swage Expander Head https://a.co/d/gd2dFWO

 

[Marc Moreau]

That is indeed pretty small. You need an Expander that will go from 7/8 to 1". The smallest I have is about 2". I'll look at it tomorrow to see if a smaller one could be made from it.

I've also seen copper pipe expanders in that size range. But I'm not sure how well they would work on stainless. I'm thinking you might need to make something.

In the meantime, here is another type. That works with a hydraulic tool. You would have to adapt it to work manually.

uxcell 7/8" Hydraulic Swage Expander Head https://a.co/d/gd2dFWO

I forget to say it must be expand for about 2 inch deep to be at the write place.

 

[Susquatch]

I forget to say it must be expand for about 2 inch deep to be at the write place.

Well in that case you are definitely going to have to either make a tool or spilt the pipe and weld it.

 

[Marc Moreau]

Probably

 

[Former Member]

You'll likely be able to source the correct size in the USA but at what cost.

Expander with a pre-heat on the pipe is likely the best solution, as to how much heat, one of our welders might best advise here, so that you have the least adverse effects in the forming.

 

[Marc Moreau]

Your are right at what price and how long to wait ?

 

[phaxtris]

No the pipe is .875 and need to expend to .940 this is only .065 removing this metal with a reamer will be scare me .

you said the wall thickness was .065?

your missing the math here, the circumference (distance around) of a .875 pipe is 2.74", the circumference of a .940 pipe is 2.95", that means the pipe will have to stretch .200 in circumference ~14%, a 14% reduction in wall thickness is going to occur, if your lucky it will occur uniformly leaving you with a pipe that is now .055" thick, but it probably wont stretch uniformly with crude tools, the piece will also work harden and be more likely to crack

i would really look for another alternative, especially considering this is a control part of an aircraft

 

[Tom O]

There are this type of swage I believe it’s for boilers.