Steering chain failure

In a previous post he said the boat was 3 years old.

There is one way of checking if the original chain is 316 as 316 is not magnetic. If a magnet does no stick to it then it is probably 316. If it does stick it is probably 304. Having said that there are various qualities of 316. The chemical composition of 316 is between various percentages - ie 16% to 18% of Chromium, 10% to 14% Nickle, 2% to 3% of Molybdenum and a small amount of carbon. 316SS which is at the lower end of these percentages is still classified as 316SS but is not as resistant to corrosion. Why do manufactures make lower grade 316SS because it is cheaper. The steering chain is possibly in a bad environment if it get wet with salt water and remains wet and exposed to air. I am not familiar with the layout of the steering on the 458. Our steering and auto pilot chains have some grease on them but not much and after 9 years they look like new. I cables have not been greased and I seem to remember something from Jefa saying not to grease the cables where they go through the sheaves. Again there is no rust on our cables.   

If magnetic - maybe 304SS but not 316SS. 

It is without doubt more corrosion resistant but also a very hard material and more susceptible to fatigue.

I would just recommend following Jefa's annual maintenance guidance?

Remove steering cables from quadrant.