yes they do wear out.. diamond come off..
Diamonds can also get dull. The sharp edges tend to eventually get rounded over. In fact very few of my old platens show a loss of diamonds, but they don’t cut very well anymore.
I’d be wary of used stones unless I was confident that there was relatively little mileage on them. A very active user could wear out a set of stones in a year or two. I sharpen probably 15 knives per month on average and they last me about three years. For me, 400 grit stones get used twice as much as the others because I always try to use it as my starting grit.
3 users thanked author for this post.