(carbon steel)It rusts.
Athin single edged blade used in the preparation of a western chef's knife.
Blue steel Sansuimon Usuba (Vegetables for professional)
Blade Blue Steel/Handle Ichii-wood
There are two kinds (kama-gata and edo-gata)
Although a non-stainless high carbon steel,the addition of various alloys makes this steel less susceptible to rusting. Moreover,the duration of edge retention is longer than its white steel counterpart. However,the addition of alloys makes this steel harder to sharpen than white steel.