I have a customer who wants me to remake these exhaust tips. I cut them and had them bent. It needs a 3" inlet for the exhaust. I took a piece of 3" stainless and put it in the vice and make it oval to get it to fit. However the customer wants it just like the old one square going into the tip and round on the other end.
How can I square this up and keep the other end round?


Racking my brain trying to figure this one out.

 

How to develop a Square to Round

 

http://www.plate-n-sheet.com.au/inde...To_Round_2.pdf

This might work better....


but again it's for sheet metal.

 

Thanks but not sure if that will help me

 

Just flatten the pipe to make it square, weld it, then work it back to round. It isn't that huge of a deal. I have done it quite a few times when I was making "NASCAR style" exhaust tips. (At least that's what people call them around here...) It helps to have a cone / anvil for reshaping, but it isn't absolutely necessary. Hell, a concentric pipe bell reducer weld fitting would work too.

OR you will need a much longer pipe and only square up one end.

PS - Those tips always sound like crap IMO. LOL!

 

we've done this at work with 16g s.s. a few times. We start with a round tube. Then use a cut off wheel and slot the other end where you want the corners to be. we took some vice grips and welded flat steel to them that's the same size we want the id of the walls to be. Clamp them down nice and tight to help flatten the panel. we then heated it with a torch and use a ballpeen hammer to shape the corners. Everything was tigged up and then and then ground smooth with angle grinders. Most likely you will still have a small radius on the id of the corners but the shape should come out noticeably square.

 

3*pie = around 9.43". Find or make something square that adds up to 9.43" and round the other side.

 

Either way will work. Its always been my experience that it's easier to make something round flat then to make something flat round.

 

It's exhaust tubing... depending on how it was formed and what type it is, it's not perfectly round to begin with - LOL! Not to mention if it's not a butt weld then an exhaust expander is going to be used somewhere anyways. Which brings me to my next idea, just go rent a exhaust expander from your local parts store and make the pipe round again. All of you guys are WAAAY over thinking this. Sometimes just doing it is much easier than thinking about it.

PS - The one he is trying to replicate isn't perfectly square...

 

Yeah I agree ^^^...I do a lot of odd jobs in my shop as well, if it were me I'd ether oval the side attaching to the tip enough to fit and just plasma the oval hole in the back side of the tip and tell the guy "it looks better than what you brought me!"... or, just get/make a square tube, weld it on and hit the other end with an expander. I hear lots of people say "ITS HAS TO LOOK JUST LIKE THIS!!" Having no idea what they are asking.

You can get the exspander at most auto parts stores for under 30$.

 

Burns Stainless sells round to oval transitions.

 

Dude I want everything they sell!!!

 

Already tried the customer wants it square. That's his one requirement.
He also says the last one cracked due to vibration but there is no way I can avoid welding it. I welded the one side and ground it flush. So I hope it's wrong enough.
I will have to see if I can find thin wall stainless rectangle or square tube then I am sure I will have to beat the crap out of it with a hammer to get an expanded to fit.

 

Well, that's a lot of vibration...you may have to grind the Top-Side-bottom smooth after welding it and the lay a 1" overlap peace that wraps all three seams and then weld it on. Maybe even gusset the that odd-ball inner corner...tho it sounds like this guy has odd taste in asteticks. Are you TIG'in this? The low heat would help avoid cracking.

 

Yep all tig

 

Can there be rounded corners or does it have to be 90° sharp bends? I guess that should have been stated in the first post to clear up any confusion on what's required. The original looks like pure **** and has rounded corners that transitions to oval pipe.

 

He didn't specify on corners. Just said square. So it doesn't matter as long as I can get it close enough to the other piece and weld it up

 

Well sounds like you're about as close to getting it as you can... if you have a box break that would be very handy to make the transition, bends don't break as easily as welds do!

....tell the guy to tune the motor so it wont shake like a sick dog and this cracking welds problem will just fix its self, haha.