Stainless Steel and Bolts

[landtoy80]

I am going to get some high grade SS metric bolts for the cat. I have hardware store SS bolts now with no problems.'
Is there any problem with using SS bolts on exhaust?
As the SS doesn't rust, will the SS nut work its way loose over time?
Does the heat have any affect on the SS?

Other than sticker shcck, is there any reason I can't use SS bolts on the rest of the 80?
I have found several body bolts that are well rusted.
Is there any place I wouldn't want SS bolts?

As for motor and drivetrain, when I need to replace bolts, do I need to get the bolt from Toyota or can I just get a grade 5 or harder bolt? If I replace a bolt that is a grade 5 with a harder bolt, could there be any reason not to use the harder bolt?

 

[RavenTai]

For the SS bolts in the exhaust find some nickel or better yet silver ($$$) anti-seize, SS exposed in rough environments (like exhaust) can still develop light corrosion

stainless is generally stronger than common steel but not as strong as high quality alloy steel, I would use OEM strength bolts in critical locations, mainly the drive train, there is a section in the front of the FSM that explains the grade of Toyota fasteners, I would use the same style and strength or just get the real deal, bolts are generally cheap at the dealer, my neighbor has a 5 gal bucket full of Toyota and Yamaha metric bolts, that is generally where look first for mine

 

[Owyhee Jackass]

You just don't want to use disimmilar metals on threaded connections. If you do you can gall the threads easily and with some metals cause galvanic corrosion.

 

[Beowulf]

>> I replace a bolt that is a grade 5 with a harder bolt, <<
>> could there be any reason not to use the harder bolt? <<

Kurt,
We had a long discussion about this several months ago. Do an archive search with grade 5 or grade 8 or something like that (80 section). I believe the concensus of the group was to always use the same grade bolt, particularly in critical areas like brake calipers, towing platforms, and recovery points.

As I recall, there were very good explanations on the reasons if you are interested.

-B-

 

[Doc]

The previous owner of my 80 didn't seem to care much about matching up bolts and threads. I've run across a couple of bad situations I had to rectify.

Thank God I have this board to teach me how and what to look for.

 

[scottm]

Stainless is fairly non-reactive, don't worry about dissimilar metals with it. Cost is it's only real downside. It does gall easier than plain steel, the surface can start to "roll up" on itself and jam in binding type applications, like threaded fasteners. Stainless rubbing on stainless seems to be worse as similar metals tend to stick to each other more than dissimilar. I often specify steels of different hardness on mating contact surfaces to reduce wear. I'd avoid stainless on very high load or frequent use fasteners, exhaust sounds like a good place for stainless.

 

[bjowett]

Try to find a stainless bolt like 304L or preferably 316L with a fine thread. The L stands for extra low carbon, carbon is what corodes in the stainless.

 

[RavenTai]

You just don't want to use disimmilar metals on threaded connections. If you do you can gall the threads easily and with some metals cause galvanic corrosion.

I am aware of dissimilar metal (aka galvanic) corrosion. Silver and nickel anti-seize have the stamp of approval from Boeing (actually required) for certain special stainless engine bolts

Stainless nickel and silver are fairly close on the galvanic scale so they are relatively inert to each other

http://www.corrosionsource.com/handbook/galv_series.htm

 

[scottm]

Can silver take the heat of an exhaust system?

 

[RavenTai]

Can silver take the heat of an exhaust system?

Silver alone may not but a high temp silver based anti-seize stands up near the combustion section of a turbine engine

2. INGREDIENTS
Ingredients CAS # WT% PEL
Castor Oil 8001-79-4 50-60 Not Established
Silver 7440-22-4 20-30 0.01 mg/m3 dust
Talc 14807-96-6 5-10 2 mg/m3 dust
Organophilic Clay 71011-27-3 5-10 15 mg/m3
Magnesium Oxide 1309-48-4 1-5 15 mg/m3

http://www.swagelok.com/downloads/webcatalogs/SilverGoop2.pdf

Silver Goop®
Oil-based thread lubricant for use on stainless steel and high temperature
alloys
Features
■ Prevents galling
■ Performs in temperatures up to 1500°F (815°C)
■ Contains a non-melting anti-seize agent
■ Lowers torque on threaded parts
■ Stays in place between mating surfaces regardless of
force applied
■ Resists moisture

Size Ordering Number
1 oz (29.5 cm3) tube MS-TL-SGT
1 lb (450 g) can MS-TL-SGC

http://www.swagelok.com/downloads/webcatalogs/MS-01-169.pdf

Would a bolt in an 80's exhaust system get over 1500°F?

 

[landtoy80]

Is this silver anti-seize different from the silver colored ant-sieze that most parts stores sell?


The nickle is 2600 F http://www.lpslabs.com/Products/Lubricants/AntiSeize.asp
How hot does the cat get?

The hardware store SS bolts with course thread I have were on the vehicle about a year.It is driven daily.THe SS bolts turned a little blue but had no corrosion and stayed tight.
I looked at one of the other SS bolts that I got from the same store and it is not magnetic. The head is stamped F593C with THE under it on the head. I know the one on the cat has THE on the head.
WHat grade would that be?

 

[LandCruiserPhil]

Would a bolt in an 80's exhaust system get over 1500°F?

With a S/C it could........not likely without

 

[RavenTai]

Is this silver anti-seize different from the silver colored ant-sieze that most parts stores sell?
QUOTE]


Yes it is diffrent from silver-colored stuff, silver goop is $300/ 1lb can, although my company overpays for everything, LPS is a good brand, that nickel they have looks good although I have never used it but thier lps "1" "2" & "3" are well used arround here


the core of cat gets very hot the hardware near it would be less