INFO: These steels are reactive materials in which the main alloying element is carbon (hence the name). These steels never contain additional alloying elements that exceed the percentage content of carbon. This results in carbon-rich steel materials with exceptionally high affinity for both sharpness and resharpening. However, because they are reactive, and comparatively low in additional alloying elements, they produce relatively delicate knives that are at risk of rusting or breaking when neglected or abused. People who exclusively use and enjoy carbon steel knives the most tend to be those who do their own sharpening.
TYPES OF CARBON STEEL:
SHIROGAMI | WHITE PAPER STEEL...
- 1: Highest carbon content variant (62-63HRC)*
- 2: Mid carbon content variant of (60-61HRC)
- 3: Lowest carbon content variant (58-59HRC)
AOGAMI | BLUE PAPER STEEL...
- SUPER: Highest carbon/alloy variant (64+HRC)
- 1: Mid carbon content variant (62-63HRC)
- 2: Lowest carbon content variant (60-61HRC)
Other knives marked “Carbon” without specific steel names are likely to be a steel similar to (if not exactly like) Kigami 3 (Yellow Paper Steel), SK5 JIS, Nihon-Kou, or AISI W108 (USA). All of these steels are approx 58-59HRC and will be slightly higher in impurities than Shirogami or Aogami.
There is further info on caring for carbon steel here.
* HRC refers to the Rockwell Hardness Scale.