Turbo guys - where can I get Inconel studs?

[Christos Adam]

I'm ready to put my turbo back in the car but I would like to use M10x1.5 Inconel studs to bolt the turbo in the downpipe.
There is currently a group buy http://www.miataturbo.net/showthread.php?t=46091" onclick="window.open(this.href);return false; but it's due in July I'm not sure if I want to wait for that...
people say that these studs usually go for $60 a piece but I find that hard to believe...

Anyway if you have any source please let me know.

Thanks
Chris

[Steve Coe]

http://www.coastfab.com/" onclick="window.open(this.href);return false;

[Steve Towers]

Ok, I'm curious - why Inconel?

[John Coffey]

'Cuz its Internet Cool!

BTW... which alloy? There are a number of different alloy Inconel fasteners: 600, 601, 617, 625, 718, X-750, and the Inconoly 800 series (800 through 825).

[Steve Towers]

by John Coffey on 22 May 2010 07:35

'Cuz its Internet Cool!.

Ok, I suppose that's one good reason But how about the actual why. Corrosion? Strength? There are lots of high end alloys - what's special about Inconel for this application?

[Mark DeShon]

by John Coffey on 22 May 2010 07:35

'Cuz its Internet Cool!.

Ok, I suppose that's one good reason But how about the actual why. Corrosion? Strength? There are lots of high end alloys - what's special about Inconel for this application?

High temperature tolerance. Necessary, no. An improvement, maybe. I'm not really up on turbo issues. 718 is probably the best choice for this application, with full strength up to 1300 degrees F and good corrosion resistance.
Mark D.
:EDIT: Parrinst says that 864 is used in automotive exhaust applications. I've never seen it because I don't think the aerospace industry uses it. I machine lots of 718 and 600, as well as some K-500 Monel.
Cost of the parts is probably mostly due to short runs, second due to all the carbide you burn through to machine it (718 is a bitch to machine), and LASTLY the cost of the material itself. 718 is about 22 bucks a pound. Hope that helps.

[Bob Beamesderfer]

More than you wanted to know:

http://en.wikipedia.org/wiki/Inconel" onclick="window.open(this.href);return false;

[John Coffey]

Ok, I suppose that's one good reason But how about the actual why. Corrosion? Strength? There are lots of high end alloys - what's special about Inconel for this application?

Its absolutely not necessary for a street or Solo2 application. There just isn't the sustained heat load that requires an upgrade over a high strength stainless stud or even a good class 10.9 or grade 8 alloy stud. Inconel/Monel (high nickel steel) turbo studs tend to be used in endurance racing or LSR efforts where the heat loads occur over longer periods of time.

[Christos Adam]

Ok, I suppose that's one good reason But how about the actual why. Corrosion? Strength? There are lots of high end alloys - what's special about Inconel for this application?

Its absolutely not necessary for a street or Solo2 application. There just isn't the sustained heat load that requires an upgrade over a high strength stainless stud or even a good class 10.9 or grade 8 alloy stud. Inconel/Monel (high nickel steel) turbo studs tend to be used in endurance racing or LSR efforts where the heat loads occur over longer periods of time.

Not it's not necessary I just had an extra hundred dollars burning my wallet and I decided to spend it in something that sounded cool... }:) :mrt:

No, not really, I did experience issues with my grade 8 studs. Granted that this was probably because I had the whole assembly heat wrapped so it was experiencing way more heat than the usual but the point is that I did have problems.
When I put the turbo back I'm planning to put only a few heat shields and allow air to escape from the mani/turbo area.

But if it's worth to doing it, it's worth to overdoing it and I honestly prefer to put this issue to bed once and for all.

[Christos Adam]

Ok, I suppose that's one good reason But how about the actual why. Corrosion? Strength? There are lots of high end alloys - what's special about Inconel for this application?

High temperature tolerance. Necessary, no. An improvement, maybe. I'm not really up on turbo issues. 718 is probably the best choice for this application, with full strength up to 1300 degrees F and good corrosion resistance.
Mark D.
:EDIT: Parrinst says that 864 is used in automotive exhaust applications. I've never seen it because I don't think the aerospace industry uses it. I machine lots of 718 and 600, as well as some K-500 Monel.
Cost of the parts is probably mostly due to short runs, second due to all the carbide you burn through to machine it (718 is a bitch to machine), and LASTLY the cost of the material itself. 718 is about 22 bucks a pound. Hope that helps.

Mark is right, is because of the inconel characteristics in high temperature - for the same reason many times it is also used in the actual turbos.

[Mako Koiwai]

Nice Link Bob ... I like USES.

[Mark DeShon]

Nice Link Bob ... I like USES.

My reference.
http://www.parrinst.com/doc_library%5Cd ... lMonel.pdf" onclick="window.open(this.href);return false;
Mark D.

[Steve Towers]

Mark will be able to relate to this: Many years ago I worked in an aerospace shop that made a number of valves for the space shuttle, one of which went on the main engine. All the metal components for the engine valve, including a very intricate and close tolerance body, were machined from Inconel 718 bar stock. It took forever and one minor screwup would result in instant scrap. I've been in shop environments for 40 years and have never heard so much complaining about machining a part, keeping in mind that the various shops I've been in have made parts from just about everything there is.

[John Coffey]

The big issue with machining nickel steel alloys is work hardening. Much worse then stainless. You go though a lot of tooling because you have to take big cuts at a slow speed. Welding it is tough too due to heat cracking. I've welded some Inconel exhaust parts for customers and you've got to get the fit-up perfect (back to the work hardening issue) and heat right. Also, the weld pool is like taffy and you sometimes gets strings hanging off the filler wire.

[Bob Beamesderfer]

The big issue with machining nickel steel alloys is work hardening. Much worse then stainless. You go though a lot of tooling because you have to take big cuts at a slow speed. Welding it is tough too due to heat cracking. I've welded some Inconel exhaust parts for customers and you've got to get the fit-up perfect (back to the work hardening issue) and heat right. Also, the weld pool is like taffy and you sometimes gets strings hanging off the filler wire.

At least it doesn't give off toxic gas like beryllium.