Chainplates are metal plates or straps, typically made of stainless steel or bronze, used to fasten shrouds and stays to a sailboat's hull, providing critical structural support to hold the mast upright. They act as the anchor point for standing rigging, distributing heavy loads across the hull.

Key Aspects and Functions:
Location: Situated along the sides of the hull, they can be mounted internally, on the exterior of the hull, or through the deck.

Components: Often consist of flat or angled metal plates (sometimes rods) that are bolted to the hull, with the top end connecting to turnbuckles and rigging.

Types: Standard flat plates are used for shrouds, while angled chainplates are often utilized for stays (forestay/backstay).

Function: They translate the tension forces from the mast and rigging into the hull structure, preventing mast failure.

Materials: Primarily high-grade stainless steel for modern boats or bronze for longevity; some advanced designs use composites.

Maintenance and Inspection: Chainplates require regular inspection for corrosion, cracking, and loose bolts to prevent failure. Common issues include water intrusion leading to crevice corrosion, particularly where the metal passes through the deck, causing rust or leaks.