The corrosion resistance of stainless steel is a godsend on saltwater boats. But stainless does have a downside when it comes to nuts and bolts, especially large ones with thick threads. The alloy has a tendency to "gall," or seize. It occurs more often when using a power driver but can happen with hand tools as well. When the two stainless components gall, nothing moves. The nut won't tighten and won't unbolt, no matter how hard you try. You need to cut off the bolt and start over. To avoid this, use an anti-seize compound such as Permatex Anti-Seize Lubricant (about $17 for an 8-ounce can). It comes with an applicator brush in the top.