I just received this sink rack and it fits my K-5846 twin bowl cast iron sink "Perfectly" on both sides!!
Another reviewer said it doesn't, but check out my picture it couldn't be better. I was also concerned about another reviewer saying it didn't fit both sides, and that was incorrect as well! All you have to do is flip it over and it fits like a glove.
Note it covers the drain holes perfect which is great for the garbage disposal side. It is a bit pricey, but this Kohler cast iron sink will last 50-60 years and this rack seems to be built to last as well!
I highly recommend this sink rack