Machine screws: 18-8 or 316 SS?

[Ortolan]

I have a 3 year-old catamaran which requires that I re-fasten every deck fitting due to 1) to lack of coring protection at any of the holes & 2) many of the heads of screws are slightly to badly rusted. I suspect the machine screws are cheap, imported 18-8 grade. Some screw heads look almost like mild steel they are so rusted!

As I don't want to do this twice, I have been researching crevice corrosion & the different grades of stainless. A posting somewhere here recommended US made 316 stainless from B & S Bolt in Virginia, but 1/4"-20 x 2" machine screws (for example) are almost $9.00 each! Would the best reasonable choice be imported 316 from a reliable source?

Russ

[Ziggy]

McMaster-Carr: Package of 10 2" 1/4-20 316 SS Machine screws: $6.75
They are a pretty reliable source.

[model 10]

Sometimes boat hardware has been pickled / pasavated so they charge a lot more than non pasavated hardware. You can buy the bag of screws for $6.75 that have not been treated and treat them yourself, or not. If you don't treat them they will show corrosion, maybe. There are fancy ways of treating stainless and simple ways. Crtric Acid is one of the ways to do this and is easy to do yourself. Basicly, you use the acid to remove any contamination and super fine roughness from the surface of the steel You can buy citric acid in a powder form places that sell wine making supplies for example.