Stock 440 Exhaust Manifold Nuts in Stainless?

[Road Grabber]

I’m getting ready to assemble an engine soon.

Does anyone sell the tubular stock manifold nuts in stainless for a 440?

If not I’m going to make them on a lathe. The original ones rust.

Thanks

 

[INTMD8]

Not sure but if you find them, use anti-seize. Stainless tends to gall when used for exhaust fasteners.

If you can make them yourself on a lathe you are likely already aware of that but thought I would mention it.

 

[snakeoil24]

Avoid stainless here they loosen easily and break off

 

[R413]

Don’t do it. I got stainless nuts and bolts for the pipe to manifold, used anti sieze. Later on they wouldn’t come off, had to cut them off.

 

[ChargerST]

Use brass nuts. McMaster-Carr has them

 

[Red63440]

Dis-simular metals don’t work well together as stated above…..

 

[ChargerST]

Brass nuts have been used on exhaust studs for a long time - they do not corrode and can be put on steel studs. Another option is copper plated steel nuts.

 

[Big Bad Dad]

Never seen brass nuts like the long tubular ones used on the HP manifolds. But standard style brass nuts used to be commonly sold in the parts stores.

 

[Road Grabber]

Thank you for the replies. If brass is a better option that makes it much easier to machine. Brass cuts easily and doesn’t need cutting oil while machining. There’s less risk of breaking a tap when threading as well.

 

[Big Bad Dad]

Thank you for the replies. If brass is a better option that makes it much easier to machine. Brass cuts easily and doesn’t need cutting oil while machining. There’s less risk of breaking a tap when threading as well.

Ya know, If you can duplicate the factory tubular nuts in brass, there might just be a market for them....

 

[Road Grabber]

I’m a retired machinist and could do that. Probably for much cheaper. I saw one steel nut going for over eight dollars. That’s a huge markup. Very simple machining.

If brass will not break during removal after long periods of time that would be great.

I’ll look into the cost of material and post some time later. Cuts easier, threads easier. You can even recycle the machined chips.


Turn it, drill it, thread and part off. A snap

I’ll offer a FBBO discount. Lol

 

[Fran Blacker]

I put SS nuts and bolts on exhaust manifold to pipe connection. Removing them was worse than any rusty bolt. Should have known better.

 

[Road Grabber]

I put SS nuts and bolts on exhaust manifold to pipe connection. Removing them was worse than any rusty bolt. Should have known better.

That’s interesting and I can see how that happens but I have used stainless bolts and nuts with lock washers on two cars now and have removed them a few times with no problem.
I have had problems with stainless threads and know what you mean.
When and if I do use them- If I can’t start and spin the nuts by hand on the thread I don’t go any further. I have noticed too that if you flip the nut over the next time and try to thread it on it causes problems.

 

[Fran Blacker]

That’s interesting and I can see how that happens but I have used stainless bolts and nuts with lock washers on two cars now and have removed them a few times with no problem.
I have had problems with stainless threads and know what you mean.
When and if I do use them- If I can’t start and spin the nuts by hand on the thread I don’t go any further. I have noticed too that if you flip the nut over the next time and try to thread it on it causes problems.

Did you use the SS nuts bolts on exhaust system where it's extremely hot like I did? Also my bolts were on for years. I don;t think I put anti on them?

 

[Road Grabber]

Did you use the SS nuts bolts on exhaust system where it's extremely hot like I did? Also my bolts were on for years. I don;t think I put anti on them?

I use stainless bolts to connect the manifold to pipe flange with no anti seize. Just bolts and nuts with lock washers.

I also use stainless nuts with flat washers over the steel studs which are resting against cast iron and have had no issues.

I just removed some stainless nuts on the studs on a motor together for over 30 years. You will have to use flat washers for the studs or they will loosen up.

There are different grade stainless. I’m wondering if that could be a factor.

I stress if you can’t spin the nut on stainless the bolt threads by hand don’t wrench it down. Put the nuts back on the way they came off.

 

[Tony Tee]

I made mine out of stainless steel. Not sure of the alloy. But it was hex stock from a surplus metals recycling store. And i did use anti seize. But the engine hasn't been run yet. But if the exhaust nuts fuse to the studs? Hopefully the studs will thread out of the head and not strip out.

 

[RJRENTON]

IMO.....with regard to stsinless steel hardware.....it would depend on the stainless steel alloy. High nickel alloy (Inconel 600, 601, 625) are capable of withstanding high temps as those found in exhaust systems and still providing the tensile strength to maintain clamping pressures. Incoloy 800H/HT are excellent high temp materials. Then the Hastelloy alloys are good to 2200°F temps. The materials are available in bar stock, rounds, flats and pipe and rods. Cost is moderate but depends on the percentage of nickel in the alloy. The more common stainless steel alloys, 304, 304H, 304L, 316, 309, 310 are good and more available.
What type of anti-seize compounds are being considered ? Graphite based or copper based of nickel based? The nickel based material is good to 2200° F, and graphite based material is the lowest temp based at 800° F.

Consider, in lieu of stainless steel is Everdur, an copper-silicon bronze-alloy that is reasonably priced and decent mechanical properties.
EVERDUR-655 is a copper-silicon-manganese alloy having the desired combination of high strength, good workability, weldability and machinability along with high corrosion resistance. It is recommended for fasteners, springs pressure vessels and general hardware. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Cu-161. Producer or source: Anaconda American Brass Company.

Before a generalization that stainless steel is "no good", one must be specific as to the alloy being considered, likewise, if an anti-seize compound is being considered, that is the temperature range to which the material is being applied? Just my opinion of course....
BOB RENTON

 

[Road Grabber]

Tremendous information there.

IMO. I wouldn’t worry about the studs and stainless corroded together. The studs typically have a coating - black ox? I have never had to use anti seize compound but I can’t see going wrong with it only I would check if your nuts loosen up later using the compound.
Without the compound worse case the two unscrew together. That’s what happens when the steel studs rust to the steel nuts anyway. The coolant spills out on some stud locations and makes a mess…unless you drain the coolant ahead of time anyway if pulling an engine.

I must have stumbled onto a better grade stainless with the bolts I used because I have had no issues.

There are many stainless grades. Machining some stainless I know 304 was a bitch compared to other machinable stainless with lead content. However you wouldn’t want the lead stainless for rust prevention and extreme temperatures. If you are a boat owner you know the best boats have better quality stainless fittings. All stainless is not the same. It’s an alloy.

I will look into the different material mentioned above. Sounds good. The price for brass wasn’t bad either and it’s even offered on eBay.

 

[RJRENTON]

"There are many stainless grades. Machining some stainless I know 304 was a bitch compared to other machinable stainless with lead content. However you wouldn’t want the lead stainless for rust prevention and extreme temperatures. If you are a boat owner you know the best boats have better quality stainless fittings. All stainless is not the same. It’s an alloy."

FYI.....There is no lead (Pb) in 304 stainless. 304 is also known as 18-8. Its the nickel content of the alloy that affords the machine-ability. Likewise, the carbon content of the alloy that affects its ultimate strength, as in 304L (low csrbon), 304/304L (dual certified), 3004H (high carbon, especially coarse grain which promotes higher strength at temperature) for example. The same designators apply to several other SS alloys as well. I would suggest that you review the material composition and mechanical properties for the different stainless steel alloys being considered, rather than a blanket or wholesale comment, that is largely not applicable. ANSI, American National Standards Institute and ASME, American Society Mechanical Engineers, are VERY SPECIFIC as to the properties of the various alloys and their use. Simply Google the alloy being considered for a wealth of information.
BOB RENTON

 

[Road Grabber]

"There are many stainless grades. Machining some stainless I know 304 was a bitch compared to other machinable stainless with lead content. However you wouldn’t want the lead stainless for rust prevention and extreme temperatures. If you are a boat owner you know the best boats have better quality stainless fittings. All stainless is not the same. It’s an alloy."

FYI.....There is no lead (Pb) in 304 stainless. 304 is also known as 18-8. Its the nickel content of the alloy that affords the machine-ability. Likewise, the carbon content of the alloy that affects its ultimate strength, as in 304L (low csrbon), 304/304L (dual certified), 3004H (high carbon, especially coarse grain which promotes higher strength at temperature) for example. The same designators apply to several other SS alloys as well. I would suggest that you review the material composition and mechanical properties for the different stainless steel alloys being considered, rather than a blanket or wholesale comment, that is largely not applicable. ANSI, American National Standards Institute and ASME, American Society Mechanical Engineers, are VERY SPECIFIC as to the properties of the various alloys and their use. Simply Google the alloy being considered for a wealth of information.
BOB RENTON

I never said 304 had lead in it. There is a stainless that is "free machining" stainless. I have cut it for many years. It's been years since machining but I had been told it was because it contained lead. I know in order to cut it "free machining" it contains sulfur and maybe some lead content.
As a machinist I didn't go into the engineering aspects. I just make setups and make the parts according to what's needed. I know it cut easier, cut down quite a bit of machine time and saved cost to the customer if it was acceptable to engineering. When I requested an engineer this suggestion once for of using it for test chamber parts he said "No -because it wouldn't satisfy extreme environmental conditions." So back to 304 and timely machining.

From this article which is pretty interesting reading:

"Stainless steels are known for their corrosion-resistant qualities given by a complex oxide protective film on the alloy surface. Chromium and nickel are the most important elements which form passive film. On the other hand, most grades of stainless steels are more or less difficult to machine in end-use conditions and are substantially different from that of carbon or alloy steels and other alloys. One procedure for improving machinability of stainless steels is the result of changes in composition by adding sulfur, selenium, lead, copper, etc. Alloying elements serve to reduce the friction forces, transverse ductility and the tendency of the chips to weld to the tool, but they affect functional (corrosion resistance, transverese ductility) and technological properties (machinability, weldability) in a free-machining stainless steel."

May I suggest looking at this article:

Free-Machining of Stainless Steels :: Total Materia Article