VETTEHIGH

Looking to have all that is needed (bolts and screws) in the engine changed and other areas changed to rust-proof . Is stainless steel or zinc plated the way to go? Any other ideas?? Thanks guys

Redeasysport

It depends on the grade of the bolts. Stainless is fine but not as strong as hardened bolts. If it has markings on it needs to be replaced with like bolts.

http://www.americanfastener.com/tech...ings_steel.asp

carguy604

Bolts (capscrews) are rated by their tensile strength (ie: Grade 2, Grade 5, Grade 8) and the substitution of one bolt for another (if you're not paying attention to the grade of the fastener) may not provide the same strength even if it's the same length, thread pitch and diameter. While a plated fastener will generally provide the same strength as a non-plated fastener, the substitution of Stainless Steel for non-stainless fasteners is guaranteed to provide less strength because stainless doesn't provide the same tensile strength. So... in a nutshell, if the fastener is subjected to load, use plated fasteners if you insist on changing. If it's just there to hold something into place you can probably use Stainless. However, before you go and change anything, it would be a good idea for you to learn how to read the head markings on your fasteners so that you know what grade each one is - before you change it. While I'm on a rant, I might as well tell you that: (a.) you don't want to mix Stainless Steel fasteners with aluminum parts unless you don't ever want to remove them again. Stainless Steel and Aluminum react with each other due to galvanic corrosion - especially when subjected to high humidity and heat (like under the hood of a car). (b.) always lube your fasteners with a Nev-r-Seize compound before torquing them in order to get correct torque settings and (c.) all things being equal, NF (National Fine thread) fasteners have greater holding power than do NC (National Coarse thread) fasteners. If you're beginning to get the idea that there's more to this than just the colour of your fasteners, you're on the right track.

dvette87

I bought stainless screws to replace my oil pan screws. Is that a bad idea?

Redeasysport

Rant as you will you did not mention SAE which is very important to car guys. If you had looked at my link you could have saved a lot of typing it show the different bolt patterns associated with grades and list thier hold capacity and types of steel..The only point you covered that I did not was the reactivity issue that I forgot about. I did not think it necessary to get on a rant


http://www.boltdepot.com/fastener-in...ade-Chart.aspx

Goldcylon

Rant what Rant???? looks like good info all around to me. I would try correctly graded stainless bolts from mcmasters. http://www.mcmaster.com/

kalister1

I know grade 8 bolts are used on the flywheel, pressure plate and maybe some suspension pieces. I would think most under hood exposed hardware would be grade 5? Are the head bolts grade 8?
Just another thought: when you use Anti-seize, you only need a tiny bit of it. There is no need to dip the bolt in the bottle.

KENS80V

Stainless fasteners are the least reactive to galvanic corrosion with aluminum due to the high nickel content. The next best would be a plated fastener while a regular unplated fastener being the worst.