About This Item
Old New Stock Mikawa Shiro Nagura Koma 4.0oz. (112g)
According to Dr. Kuniichi Tawara who is a Metallurgy doctor, and very famous Japanese sword researcher, Koma molecule is 10 to 20 micron. It is used right before sharpening Uchigumori whetstone in Japanese sword sharpening to delete whetstone marks from one before process Chu Nagura sharpening. For razor sharpening, it is used one before the process sharpening by fine grit whetstone like Nakayama, Ozuku, Wakasa, etc.
I t is for sharpening Japanese sword or razor blade or high carbon steel Koma has used by Japanese sword sharpening masters and the other craftsmen for a long time, so it has run out the mine at first. That is why it is dealing with higher price like double of the amount or triple of the amount comparing with the other Nagura layers. Koma is one of the twelve layers of the Mikawa shiro nagura mine. It is hardest to find among Mejiro, Tenjo, Botan, Koma, Ban, and Atsu, etc. Those nagura names derive from layer in Shiro Nagura mine. Koma is not only the finest Shiro Nagura in the layers, but it is also fast cut.