Stainless, galvanized, or rusty....?

[Wade Lippman]

I bought a small hoist at an estate sale today and had to take it apart to get it home. The fasteners are pretty rusty, but with liberal applications of WD40 I only broke one lag screw. It will be used in a lake in upstate NY.

I got the fasteners apart, so I assume I can get them back together; but as long as i have it apart, maybe I should replace them. Stainless will be pretty expensive and take a week to get here. Obviously the manufacturer thought galvanized was adequate. But of course the existing fasteners are free.

So what do you think; stainless, galvanized, or rusty?


Naturally the lag screw that broke was the fastener that would cause the most trouble, but that's life.

[Ted Calver]

I would go stainless for this application.

[Jim Becker]

Stainless would certainly be much more corrosion resistant...but AFAIK, stainless may not be as strong. Check the "grade" of the fasteners to insure that if you replace, you replace with the right products.

[Rich Enders]

Of course stainless for a lake application... BUT, Jim's comment above has to be considered. Commonly available 304 stainless bolts (A2) are about equal to commonly available mild steel bolts (Type 2). But if your bolts are hardened they cannot be equaled by stainless. 316 stainless steel bolts (A4) are better than mild steel bolts, but hardened steel (Type 5 or Type 8) is better still. You can test for hardening by seeing how easy it is to mark the bolt with a file. Of course rust will degraded the strength so you probably do not want to reuse the rusty ones.

[Lee Schierer]

I agree completely with Rich, with something as critical as a hoist you don't want to degrade safety with sub-standard bolts. Stainless won't rust as easily, but the strength is pretty low. Look at the bolt heads and match the little hatch marks and numbers with your new bolts. Also look closely at the washers if the bolts are grade 5 or 8 as the washers need to be hardened washers as well.

[Shawn Pixley]

As others have implied, stainless is brittle. If strength is needed, go galvanized. I say this as an ex saltwater boater who abhors rust, but in this case I would argue against the stainless.

[Myk Rian]

The fasteners are pretty rusty, but with liberal applications of WD40 I only broke one lag screw.

There's your problem. Who told you WD-40 breaks rust? It doesn't, it helps PREVENT rust.
Use a 50/50 mix of Acetone and auto trans fluid.

[Ole Anderson]

Lag screw? Not a machine screw or bolt? Can you attach a picture of the hoist as there are a lot of different ones used in a boating situation. A boat hoist, a trailer winch, or what? Just curious. Good news is that you won't be dealing with a saltwater environment. Even so, any non-stainless fastener left outside for years will eventually rust. And typically grade 5 or 8 bolts are not galvanized. Dissimilar metals can hasten the corrosion. With stainless, usually the fastener won't corrode, but it can hasten the corrosion of the other metal, particularly if it is aluminum. If strength is critical, sometimes you can stick with stainless and go up one size by drilling and re-tapping the hole. That is what I did with many bolts on my Jeep.

[Wade Lippman]

It is a very small aluminum hoist. Strength is not a big deal. The lag bolts were into the runners.

I read that while galvanized would rust, stainless might corrode the aluminum, so I was all set to use galvanized; but the galvanized was almost as expensive (and you all recommended stainless) so I got SS. If the aluminum corrodes, I can always use 1/2 rather than 3/8". Maybe I will put some old galvanized down there to act as a sacrificial anode.