stainless bolts

-
I don't see a set for a Magnum. Your going to have to measure the size you need and go to their web site and buy them by size.
 
mopardemon340 said:
yea i know anti seize is needed
Click to expand...

Just don't use a copper or zinc based anti-seize when messing around with dissimilar metals. Something non conductive like rtv works well in this non critical area.
 
T56MaxTorq said:
Just don't use a copper or zinc based anti-seize when messing around with dissimilar metals. Something non conductive like rtv works well in this non critical area.
Click to expand...
Please school me by elaborating on this one.
 
Dana said:
Please school me by elaborating on this one.
Click to expand...

To prevent galvanic corrosion. When two dissimilar metals contact each other with the help of an electrolyte around like water, sea or road salt; it causes a slow reaction we all know as rust (oxidation.) When you have or add a very reactive metal like zinc, copper, aluminum to the reaction, it accelerates the cycle.
 
Given my limited metallurgical and chemical knowledge, i have no reason to doubt this. However it most likely applies better to a submerged or at least mostly saturated atmosphere. I've lived in the good old rust belt my whole life. Every nut and bolt(unless hardness is an issue) that gets replaced around here automotive or not gets stainless with either nickel or copper anti-sieze. Every chassis component, exhaust, brushhog, tractors, rototiller, (SALTSPREADER) ETC. Galvanic corrosion on intake manifold bolts??
 
It's more of a proper maintenance practice than anything. This is why there is so many types of anti seize - copper, nickel, graphite, moly d, etc. Have you ever went behind your work and tried to seperate a stainless bolt with the wrong anti seize driven into an aluminum part a decade later? I'd hate to hear about someone who uses stainless bolts into an aluminum head (not the case here) and they are seized or break off next service. Or puts nickel anti seize on their brakes banjo bolt that uses a copper crush washer. Point is, please choose the right fastener and anti seize for the parts you're assembling, keeping in mind corrosion. It takes a backseat to strength but it is equally important. Like it or not, everyone's ride is slowly decaying away. Just ask a body man.

In the aircraft industry we use lots of anti seize and have had folks mistakenly use moly d with silicone on fasteners exposed to the engine oil instead of just moly d. Just a little bit of that silicone in the oil system contaminated 12 gallons of oil. The oil actually foamed up and the engine lost 8 gallons vented overboard through the breather. Emergency declared and engine was shut down in flight. Happens more than you think.
 
so i need to use anti seize with 304 stainless.. i was told that i dont need to by someone who dont use it an said they never had an issue
 
The thing with stainless, especially stainless on stainless is, if you dont get it started right or the two thread pitches aren't exactly a match it creates friction fast which makes heat. That kind of heat workhardens stainless and it will guald to itself making it completely unusable in less than one full revolution. Same thing happens when you try to use a standard tubing cutter on stainless brake line. Making it impossible to flare. IMO in an engine fastener application, you could get by with a light oil and caution on how you start the thread. Stay away from air tools! Don't forget a little anti-sieze on your spark plugs.
 
Stainless steel is steel with nickel added to create a stainless alloy.The amount of nickel can vary and give different amounts of corrosion resistance.The strength will depend on the parent steel...if it is high carbon with nickel added the bolt will be very strong.If it is mild steel with nickel added it will be as strong as mild steel...nickel is not overly strong or hard.
the strength of the bolt will be indicated on the head...3 ticks would be grade 5,5 ticks would be grade 8 (aircraft quality)
anything with an allen head is grade 8.
 
Unfortunately many stainless manufacturers do not use "ticks". 316 is supposed to be 68pct iron-17pct chromium-12pct nickel. 18-8 uses less nickel (about 8pct) which is why it responds mildly to magnetism. They both carry a tensile strength of aprox. 75,000lbf/sq-in. Which falls between grade 2 and grade 5 carbon steel tensil strength, for the size bolts we deal with in the automotive side. Again just a general guideline. As with everything and like ir3333 was saying, expect a variance between manufacturers. Personally I torque all engine fasteners (exterior) the same as the motors manual torque spec and never had any issues.
 
It's wise to just use a general torque chart for the bolt or nuts size, threads per inch, and composition. Any special torque on a fastener will always be listed in the manual. Anything else, just use the charts. Same for pipe fittings.
 
Well if you have a gasket that is supposed to crush a certain amount, it is based on torque. So if you use a lighter torque because of the fastener composition, there has got to be a give and take.
 
I'm not trying to fight you because this is great discussion, but any fastener with a gasket is going to have a torque specification. You should never reduce a torque against that spec in the first place.
 
No No please don't get me wrong it is just a good discussion. And that is exactly what i'm saying, either go by the correct torque spec or don't use a different composition fastener. Some times you might be overtorqing the stainless, but its not like it a BIG RISK on an intake. Now i don't use stainless bolts on exhaust manifold to head. I use grade 8 with a good copper never-sieze. But i do use stainless fine thread nuts on the exhaust studs.
 
Last edited:
I think the tensil strength really gets tested in exhaust manifold heat cycles. 316 cannot take it.
 
anyone have any idea what torque spec i should use with 304ss on the intake. i tried to use the 35ft lbs that it calls for but all ill say is that it didnt go as planed. 15ft lbs worked for the middle torque..
 
I've got 30ft lbs. what says 35? did you break a bolt?
 
Dealt with SS bolts alot on bike's when it was popular to pull every exposed bolt and replace with polished SS. Doesn't take long for the ss to weld itself into Al casting. Nightmare to disassemble a year or 2 later. So agree with a lot of what's being said about galvanic corrosion/electrolysis. X's 2 on being careful starting them, and I'm not convinced on the grading system on SS fasteners. They just seem to break when they shouldn't.The draws backs outweigh the "look nice" factor for me
 
mopardemon340 said:
anyone have any idea what torque spec i should use with 304ss on the intake. i tried to use the 35ft lbs that it calls for but all ill say is that it didnt go as planed. 15ft lbs worked for the middle torque..
Click to expand...
and it'll loosen up going down the road.......
 
You must log in or register to reply here.
-

Back
Top