I have never bought any hand stones new. I have gotten dozens of many types, however, in various acquisitions. I had three new 6" brown Gesswein hand stones that worked pretty well. These were about 6x1/2x1/8" (roughly). I use flat stones like this a lot to touch up HSS tooling when I'm running my (small, manual) lathe. However, through a combination of breakage, loss, and perhaps some misuse (is there a hand stone FAQ somewhere?) I find I'm about out of small flat stones for general shop work on HSS.
What exact products do you recommend, and where do you buy them?
Grant Erwin Kirkland, Washington