Asano Nagura speed

[maxim]

How Asano Naguras speed up very hard and fine stones.
I know it is on razor, but same happens with knives.
Razor have very small surface aria that touches the stone so you can imagine it will be even more swarf with a knife

[tk59]

I'm gonna need to mark these nagura. I keep forgetting which is which.

[maxim]

Here is some Kanjis to help

http://www.japanesenaturalstones.com/Nagura-s/1836.htm