Uchikumori Suita Japanese Natural Finishing Stone - 1312g

Size: 209mmx80mmx35mm

Weight: 1312g

Additional Information:  An Uchigumori Suita from the Ohira mine.

In terms of hardness, it falls squarely in the medium range for an Uchigumori Suita—neither too hard nor too soft—making it exceptionally well-suited for sharpening woodworking tools. I recently heard from Mr. Tsuchida that back in the Showa era, many carpenters favored harder Uchigumori stones as nakato (medium stones) due to their aggressive cutting ability.

I tested this out recently: after establishing the bevel on this watetsu chisel with a Naniwa Hibiki #1000, I jumped straight to this Uchigumori without using any synthetic #2000 or #3000 stones in between. Within just a minute or two, it completely erased all the scratch patterns left by the #1000 grit. The intricate texture of the watetsu jigane emerged with remarkable clarity, leaving the entire bevel with a beautiful kasumi finish.

The stone has no toxic or harmful lines, though there is a single natural “su” that should be avoided during sharpening.