ANODE SHAFT 40 MM

Function and technical context

Shaft anodes are cathodic protection elements designed to be installed directly on the boat's tail shaft, acting as a sacrificial metal that absorbs galvanic corrosion rather than allowing it to attack expensive metal components such as the shaft itself, propeller or water bearings. This 40 mm anode works within the underwater transmission system, in the area most exposed to the marine environment, where the electrochemical action of salt or fresh water can degrade the metal in a few weeks if there is no adequate protection. Without proper cathodic protection, the shaft can suffer pitting, material loss and structural weakening that compromises both the maneuverability and safety of the vessel. The 40 mm diameter guarantees a precise fit on axles of that size, ensuring the electrical contact necessary for the protection to be effective.

When to replace this part?

Shaft anodes should be inspected at least once a season and replaced when they have lost approximately 50% of their mass, since below that level the protective capacity is significantly compromised. Symptoms indicating a depleted or missing anode include visible pitting on the tail shaft, metallic discoloration in the propeller area, or accelerated corrosion on the stern hardware. The professional recommendation is to renew the shaft anode at each annual grounding as a preventive measure: the cost of an anode is minimal compared to replacing a shaft damaged by galvanic corrosion.

Compatibility table