Galvanized vs. Stainless Steel Anchors

Stainless costs two to three times as much and holds no better. Here is the honest case for each — including why we still make both.

A galvanized anchor and a stainless anchor of the same design hold identically — the shape does the work, not the finish. What differs is how each one ages, what it costs, and how it looks doing it. Galvanized is the better value for a working primary anchor. Stainless is the better choice when the anchor lives visible on a bow roller and you would rather not look at rust streaks down your topsides, that is why stainless steel is used for bow rollers and most deck gear. Both are defensible; they are just not the same purchase.

We build every M1 and M2 in both, so we have no stake in which one you pick. This is what we would tell you on the phone.

The two are protected in completely different ways

Galvanizing is sacrificial

Hot-dip galvanizing bonds a zinc layer to steel. Zinc is less noble than steel, so it corrodes first and protects the steel underneath — including at scratches and chips, where the surrounding zinc keeps protecting the exposed metal. That is the important property: galvanizing does not have to be perfect to work.

The cost is that it is consumed. Dragging an anchor across sand, rock and coral wears the coating, and after enough seasons the anchor needs re-galvanizing — a few hundred dollars at a hot-dip shop and a little bit of work, and the anchor comes back essentially new. How long depends entirely on use: heavy cruising in coral might mean three to five years, weekend sailing in mud far longer.

Stainless relies on a passive film

Stainless resists corrosion through a thin chromium-oxide layer that reforms whenever oxygen is available. That works beautifully in aerated water. It works much less well in the two situations an anchor actually lives in: buried in seabed mud with no oxygen, and sitting wet in an anchor locker.

In low-oxygen, high-chloride conditions the passive film cannot repair itself, and stainless becomes vulnerable to crevice corrosion and to chloride stress-corrosion cracking. The second one matters more than the first, because it is not visible: it propagates inside the metal, and a stainless part can look immaculate right up until it fails. This is exactly why we make our anchors and chain hooks from 2205 duplex rather than 316 — the load-bearing connections live permanently in that low-oxygen condition.

For an anchor the risk is lower than for a small highly-stressed fitting, because the sections are massive relative to the loads. So a stainless steel anchor might look great for a very long time but probably needs to be replaced every 10 years, we recommend changing the bolts every 5 years for extra safety.

Side by side

What the difference costs

Our own pricing, for identical anchors in the two finishes:

Put that in context. On a 25 lb anchor the stainless premium is about $950 — roughly two or three re-galvanizings, and a stainless steel anchor lasts about three times as long. Both offer a reasonable choice, galvanized option offers lower upfront cost but more upkeep time and cost down the road and a stainless option offers longevity and better aesthetics.

Which should you buy

• Buy galvanized: for lower up front cost and expected life of 3-5 years when actively cruising. Re-galvanizing cost of $200 – $300.
• Buy stainless if the anchor is visible and the boat’s appearance matters, if you cannot easily get an anchor re-galvanized and want the anchor that can last 10 years and are ok with a higher upfront cost.
• Consider one of each we also offer quick connect stainless steel anchors that allow for quick assembly/disassembly for smaller boats. Stainless Steel Quick Connect Anchors

Common questions

Does a stainless anchor hold better than galvanized?

No. Holding power comes from the anchor’s geometry, its weight and the seabed — not from the finish. A galvanized M2 and a stainless M2 of the same weight set and hold the same. Anyone claiming otherwise is selling something.

How often does a galvanized anchor need re-galvanizing?

Entirely dependent on use. Weekend sailing in soft mud can go a decade or more; full-time cruising with hard sets in coral and rock might mean every three to five years. The signal is surface rust spreading over broad areas rather than at isolated chips. Re-dipping costs is usually about $250 -$350 and requires a little work (clean up after) but returns it to as-new protection.

Can I use a stainless anchor with galvanized chain?

Yes, and it is common. There is a galvanic couple between the two, but the chain is the sacrificial side and the connection spends most of its life out of the water in the locker, so the practical effect is small. Usually the fist few links of chain rust prematurely but the rest of the chain does not degrade, painting the first few links also helps mitigate the issue.

Why do stainless anchors cost so much more?

Raw material cost is part of it, but fabrication is the larger share. Marine-grade stainless is harder to cut, weld and finish than mild steel, it work-hardens, and achieving the polished finish people expect is labor-intensive.

Will a stainless anchor rust?

It will show surface tea-staining, particularly in warm water, which polishes off. The concern is not cosmetic rust but crevice corrosion and stress-corrosion cracking in low-oxygen conditions — damage you cannot see. Inspect the shank-to-fluke joint and any bolted connections rather than judging by how shiny the surface looks. We recommend changing the bolts on our stainless steel anchors every 5 years and changing the anchor itself every 10 years.

Keep reading

• Anchor sizing — get the weight right before you choose a finish
• Anchor choice — how the modern designs differ
• M1 Performance and M2 Performance
• Chain hooks — why the connecting hardware uses a different alloy
• The anchor bolts — why a bolted anchor is not a compromise
• All guides and the knowledge base