How to Identify Your Common US Anchor Chain

Anchor Chain Types in the US
In the US, the main types of anchor chain are categorized by their grade and material, with some variations in link design. Here's a breakdown:

BBB - Anchor Windlass Chain

A short link chain of normal commercial quality. Constructed from low carbon steel. It has a uniform pitch short link and works well with gypsies. It used to be the standard for windlasses, but it has largely been replaced by G4 Chain. It is marked approximately every foot with the manufacturer's symbol and grade marking: 3B

G4, G40, G43 - High Test (HT)

This is the standard for most windlasses today. Made from high carbon steel, it has twice the working load of BBB chain which allows a smaller chain size to be used. It is marked approximately every foot with the manufacturer's symbol and grade marking: G4, G40, G43 or G400.

G30 - Proof Coil

A general-purpose chain of normal commercial quality. Constructed from low carbon steel. Proof coil chain doesn't have a uniform pitch and does not work with windlasses. It is marked approximately every foot with the manufacturer's symbol and grade marking: 3, 30 or 300