In this video, I review the 320 grit Nubatama waterstone from the Ume series of stones. The knife I use to demonstrate this stone is an old Gerber cleaver from my college days in the 70's that I haven't used in years. It is (I believe) a 440C stainless steel blade. It has an uneven bevel and can only slice cut a piece of paper with some difficulty. The stone is porous but saturates in a few minutes. It generates a modest amount of mud, with the mud helping to cut more aggressively. There is minimal dishing of the stone. It very quickly helps me establish a consistent edge (flat bevel), giving me an edge that easily slice cuts paper and can begin to push cut. This stone would be an excellent coarse stone for a set of stones if you don't require extreme reshaping, but want to get an edge useful for basic cutting.
"Wow! For a long time I have been looking for a coarse stone to replace my Bester #500,and I finally found the replacement. The Nubatama ume 320,cuts faster,dishes less and doesn’t dry out as fast,and the really big plus is that it is twice the size. At least for me it will be a money saver,because it will at least last me as long as 3 Bester #500 stones."