| Materials and Corrosion Protection |
| Hot-dip galvanized carbon steel | Common choice for all-chain and mixed rope-and-chain anchor rodes. | Strong and widely available. The zinc coating helps protect the steel from corrosion; abrasion and time can wear the coating. | Look for marine-suitable chain, consistent galvanizing, traceable specifications, and a windlass-compatible link pattern. |
| Stainless steel, commonly 316 grade | Available in some anchor-chain sizes and link styles. | Offers good corrosion resistance in many marine environments, but strength depends on the specific chain specification. Crevices, deposits, and oxygen-poor conditions can still contribute to corrosion. | Confirm the chain’s certified strength and intended anchoring use. Do not assume stainless chain is stronger than galvanized chain of the same diameter. |
| Uncoated or inadequately protected steel | Not generally preferred for a marine anchor rode. | Exposed steel is susceptible to corrosion in seawater and may require additional protection and maintenance. | Use only when the product specification and corrosion-control plan suit the application. |
| Chain Grades and Intended Use |
| Grade 30 (G30) | General-purpose chain grade commonly offered for anchoring. | Typically a lower-strength option than higher-strength anchor-chain grades of comparable size. Exact properties depend on the governing standard and product. | Check the manufacturer’s standard, certified proof or breaking-load data, and whether the chain is explicitly intended for anchoring. |
| Grade 40 (G40) and Grade 43 (G43) | Higher-strength grades commonly found in anchor-chain ranges. | May provide greater rated strength than lower-grade chain at a comparable nominal diameter, but grade numbers and ratings must be interpreted using the applicable specification. | Compare certified values for the exact chain, not grade labels alone. Confirm compatibility with the windlass and connecting hardware. |
| Grade 70 (G70) transport chain | Often sold for cargo tie-down and transport applications. | A high-strength transport-chain designation does not, by itself, make a chain suitable for anchoring or continuous marine exposure. | Use for anchoring only if the chain is specifically certified and approved for that service by its manufacturer. |
| Grade 80 and other lifting-chain grades | Designed for specified lifting applications when supplied and used under the relevant rules. | A lifting rating is not an anchor-chain rating. Intended use, link design, corrosion protection, and inspection requirements differ. | Do not substitute lifting chain for anchor chain unless the product documentation explicitly approves that use. |
| Dimensions, Fit, and Sizing |
| Common metric nominal diameters | Examples include 6 mm, 8 mm, 10 mm, and 12 mm. | These are common size increments, not a universal recommendation for a particular vessel. Required size depends on the boat, anchoring conditions, chain grade, and system design. | Follow the vessel or windlass manufacturer’s sizing guidance and verify the chain’s certified ratings. |
| Common imperial nominal diameters | Examples include 1/4 in, 5/16 in, and 3/8 in. | Imperial and metric chains with similar nominal diameters may have different link dimensions and may not run correctly in the same windlass. | Match the chain standard and actual link geometry to the windlass gypsy; do not select by diameter alone. |
| Link dimensions | Check nominal diameter, inside length, and inside width; dimensions vary by chain standard and product. | The gypsy engages the chain links, so link pitch and width are critical to reliable hauling and lowering. | Use the windlass maker’s chain-calibration specification and the chain supplier’s dimensional data. Test fit before installation. |
| Chain length and rode configuration | All-chain rode or a combination of chain and anchor rope. | The appropriate length depends on water depth, expected scope, anchoring conditions, and vessel requirements. | Plan for the intended operating depths and keep a suitable reserve. Secure the bitter end to the vessel using an appropriate arrangement. |
| Connectors and end fittings | Shackles, swivels, and joining links must suit the chain and anchor system. | A mismatched or weak connector can limit the strength of the entire rode and may not pass through the windlass. | Check rated capacity, pin security, corrosion compatibility, physical clearance, and gypsy passage. |