There are more types of steel than you can shake a cutting wheel at, but most do not work well in a marine environment.

Boats require stainless steel for most hardware applications – and high-grade stainless at that. Eric Johnson, technical standards manager at the American Boat and Yacht Council, says his organization recommends type 304 or 316 stainless for most applications.

Type 316 stainless is the type most often used in boating applications. It's non-magnetic and more resistant to salt than other stainless steels because its composition includes molybdenum. It can be used on the exterior, and even underwater, though submerged hardware is more commonly made of bronze or high-grade plastic.

Type 304 stainless, also known as 18-8 alloy (it is 18 percent chromium and 8 percent nickel), is another type used on many vessels. It is less resistant to corrosion but more resistant to wear, and therefore commonly used for hardware that includes moving parts.

– Theodore J. Sawchuck