Prop shaft wear and tear


I’m going over my hiorth propulsion unit to check for wear and tear. I noticed that the lip seals for the prop shaft has done a very good job and there are actually grooves in the shaft for each seal. This particular shaft is not stainless but it is hardened, the surface of the rod is really hard.

Is this to be expected? Do you change shaft on a regular basis? You guys using SS, do you see the same thing?