Jamestown Distributors is a large supplier of boat anchors, anchor chain, chain links, cables and other rigging and anchoring supplies. Danforth Anchors are especially popular. Almost all of the anchoring supplies, including shackles, thimbles, chain, and the anchors themselves, are made out of hot-dipped galvanized steel, which helps to prevent corrosion, is fairly light-weight, yet cost effective.
Grade 30 proof coil is a general purpose chain of standard commercial quality. Grade 30 proof coil is commonly used for mooring chain, but has one major drawback: mooring setups using proof coil will only accept shackles through the end links. The middle chainlinks do not permit enough space for a shackle pin. A better alternative for mooring rigs is "long link" chain, because bridles or attachment sections to mooring balls easily splice in with a shackle mid-chain. Grade 30 proof coil chain is made from low carbon steel. This chain is frequently used for fabricating tow chains, logging chains and, when appropriate, tie down or binding chains. Hallmarked every foot or so with manufacturer's symbol and grade marking: 3, 30 or 300.
Grade 40 High Test chain has the same strength levels as Gr 43 but the dimensions of the chain links are smaller using ISO standards. Primarily used for boat windlasses, this grade has become a standard for the marine industry. The Grade 40 designation was exclusively used by ACCO Chain until 2005 to designate their High Test grade chain. They now use "43" in keeping with the rest of the industry. The chain is hallmarked "G4". Not for overhead lifting.
Grade 43 High Test is a higher strength chain used for years in the trucking industry for tie downs that meet DOT specifications. Made from a higher carbon steel, its strength surpasses proof coil working load limits, size for size, by a factor of 2 to 1. Hallmarked every foot or so with manufacturer's symbol and grade marking: 4, 40, 43 or 400. If using for anchor rodes with a windlass, check with the windlass manufacturer for compatibility. Not for overhead lifting.
BBB (Bend Before Break) chain is carbon steel, general purpose chain with short compact links. The short link makes chain more flexible and ideally suited as anchor chain because it fits most major brand windlasses. Some applications may require adding attachments for oversized end links. The compact spacing of the links also adds more weight per length, increasing catanery and holding power of the anchor rode.
For marine applications, hot dip galvanized finish helps extend usable life of chain. Stainless steel chain can be used for anchor rodes, but will not fare well under constant prolonged submersion such as moorings, because the lack of oxygen will cause rapid deterioration of stainless steel metals.
Whenever rigging anchor rodes or mooring rigs, be sure to mouse any shackle pin attachments with a locking wire or plastic wire tie.