Are these for real? Donut mandrel bends
 

http://www.hrpworld.com/index.cfm?fo...action=product

http://www.hrpworld.com/client_image...cts/1227_1.jpg

I've seen them used for real tight radius's, a guy on the forum actually had one sitting in his garage when he said he was going to be building his own exhaust.

those are nice for buildung mani's...

allows you to weird bends that arent made

Yes, that's how you make these:
http://www.cyrilhuzeblog.com/wp-cont...ds/wanted1.jpg

http://www.cyclequest.com/Arizona/Cl...0P1/Titan2.jpg

http://media.westcoastchoppers.com/p...s/24116/31.jpg

http://media.westcoastchoppers.com/p...s/24112/19.jpg

Yes, they are a welded seam type deal. We used them on our DP's for Scion's.

My buddy bought some and used them to fab up a tight bending turbo intake pipe. I'll see if I can find some pics somewhere because it looked niiice..

its too expensive there, plumbng suppliers have them for cheaper i think...i can get those made from a friend also, not sure how much, but not nearly what they want...

jc whitney has em too

Are they stamped and welded?

ive only seen stamped, but those look like tha they have a seam.

road/race sells them too. I think they're like seven hundred dollars.

I wanna know how they are actually manufactured.

I would think halves are stamped and welded. I'm too stupid to figure out any other way. :dunno:

pretty sure they're formed cake-tins and welded halves.

http://www.roadraceengineering.com/p...rts/donuts.jpg

The inner seams have to be finish welded when you cut it apart as well. Only the outside seam is completed.

I've seen them hydro-formed from flat plate and then welded on the OD seam. The ID has no seam on the hydro-formed units.

Ahh ok, thanks. That makes sense. For tight radii I've been using ATP's tight radius 90's and 120's. This is another interesting option.

Yes they work awesome but they have an inside seam that needs to be welded.

Now links to less expensive versions. I know you have them!