COLLARIN EJE CORTO 22 mm. (ZN)

Function and technical context

The 22 mm short shaft collar made of zinc (ZN) is a galvanic protection component that is installed directly on the tail shaft of the boat, in the transmission area between the engine and the propeller. Its main mission is to act as a sacrificial anode, absorbing electrolytic corrosion that would otherwise attack the shaft itself, the propeller and other submerged metal elements. As it is zinc, it is especially suitable for vessels that operate in salty or mixed waters, where galvanic corrosion is more aggressive. Without this collar in good condition, the shaft is exposed to pitting and accelerated wear that can compromise alignment, cause abnormal vibrations and lead to costly powertrain repairs.

When to replace this part?

The clearest symptom that the zinc collar has completed its cycle is the visible reduction in its mass: when the anode has lost approximately half of its volume, it must be replaced before it is completely consumed and the shaft is left unprotected. It is recommended to inspect it at each beaching or, at least, at the beginning and end of each nautical season; In areas with high water conductivity or stray electrical currents, wear can be considerably faster. Replacing the collar preventively is the most economical measure to protect the shaft and propeller, thus avoiding much more costly workshop interventions due to advanced corrosion.

Compatibility table