Aogami 2 (Blue 2) knife steel
Quick answer
Aogami 2 (Blue 2) is a carbon kitchen knife steel running about 61 to 63 HRC. Edge retention is very high, toughness moderate, corrosion resistance very low and ease of sharpening high. It is found in Traditional Japanese carbon knives.
The Rockwell hardness figures are published by the manufacturers. The one to five scores are relative rankings rather than measurements.
| Steel | Hardness | Retention | Toughness | Corrosion | Sharpening |
|---|---|---|---|---|---|
| X50CrMoV15 | 56 to 58 HRC | 3/5 | 5/5 | 5/5 | 5/5 |
| X55CrMo14 | 55 to 56 HRC | 2/5 | 5/5 | 5/5 | 5/5 |
| 1.4116 | 55 to 56 HRC | 2/5 | 5/5 | 5/5 | 5/5 |
| 440C | 58 to 60 HRC | 3/5 | 3/5 | 5/5 | 4/5 |
| AUS-8 | 57 to 58 HRC | 3/5 | 4/5 | 4/5 | 5/5 |
| AUS-10 | 58 to 60 HRC | 3/5 | 4/5 | 4/5 | 4/5 |
| VG-10 | 60 to 61 HRC | 4/5 | 3/5 | 5/5 | 3/5 |
| VG-MAX | 60 to 61 HRC | 4/5 | 3/5 | 5/5 | 3/5 |
| Ginsan (Silver 3) | 60 to 61 HRC | 4/5 | 4/5 | 5/5 | 4/5 |
| SG2 / R2 powder steel | 63 to 64 HRC | 5/5 | 2/5 | 5/5 | 2/5 |
| ZDP-189 | 64 to 66 HRC | 5/5 | 1/5 | 4/5 | 1/5 |
| Shirogami 2 (White 2) | 61 to 63 HRC | 4/5 | 3/5 | 1/5 | 5/5 |
| Aogami 2 (Blue 2) | 61 to 63 HRC | 5/5 | 3/5 | 1/5 | 4/5 |
| Sandvik 14C28N | 58 to 60 HRC | 3/5 | 4/5 | 5/5 | 4/5 |
What is Aogami 2 (Blue 2)?
Aogami 2 (Blue 2) is a Japanese kitchen knife steel hardened to roughly 61 to 63 on the Rockwell C scale. White steel with tungsten and chromium added, which buys edge retention at some cost in how easily it sharpens. It rusts exactly as readily.
Rockwell C hardness is measured by pressing a diamond cone into the steel under a set load and reading how deep it goes. Kitchen knives span roughly 55 to 66 HRC. The figure measures resistance to deformation, which correlates strongly with how long an edge stays aligned, and it says nothing directly about toughness or corrosion resistance.
What the hardness actually buys you
At 61 to 63 HRC this steel supports a very thin, acute edge that stays sharp through a great deal of cutting. That is the central trade in kitchen knives, and it is metallurgy rather than marketing: a harder edge is thinner and more brittle at its apex, so it survives longer in clean cutting and fails by chipping rather than rolling when it meets something hard.
At this hardness the knife will chip rather than roll. No bones, no frozen edges, no twisting in the cut, and no pull-through sharpener, ever. A chip needs far more work to remove than a rolled edge does.
Sharpening and maintenance
Ease of sharpening scores 4 out of 5 here. This steel comes back quickly on almost any abrasive, which is a genuine advantage for anyone who sharpens infrequently or is still learning.
This is a carbon steel, not stainless. It will darken into a patina within days and will spot with rust if left wet even once. Wipe it dry immediately after every use, including after a rinse, and expect it to react with acidic food.
Knives and sharpening gear
- BABOSTOW
BABOSTOW Knife Sharpening Stone 1000/6000 Grit with Base & Angle Guide
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KING KW65 1000/6000 Grit Combination Whetstone with Plastic Base
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Common questions
How hard is Aogami 2 (Blue 2)?
About 61 to 63 on the Rockwell C scale, as published by the makers who use it. For context, kitchen knives run roughly 55 to 66 HRC overall, so this sits toward the harder end of the range. Hardness is measured by indentation depth under a set load.
Is Aogami 2 (Blue 2) a good kitchen knife steel?
It is a good choice for the right cook. White steel with tungsten and chromium added, which buys edge retention at some cost in how easily it sharpens. It rusts exactly as readily. Whether it suits you depends far more on how you maintain knives than on the alloy itself: it rewards someone who wants a knife that comes back quickly with minimal fuss.
Does Aogami 2 (Blue 2) rust?
Yes. It is a carbon steel with minimal chromium, so it will develop a grey patina within days of use and will spot with orange rust if left wet. That is normal and expected rather than a defect, and it is avoided by wiping the blade dry immediately after every single use.
How do I sharpen Aogami 2 (Blue 2)?
On a whetstone, around 1000 grit to set the edge and 3000 to 6000 to refine it. A pull-through sharpener tears at this hardness rather than abrading cleanly, and it will leave the knife worse than it found it.
Does the steel matter more than the blade shape?
Usually less. How thin the blade is behind the edge, and the angle it is ground to, decide how a knife feels in the cut far more than the alloy does. A well ground knife in ordinary steel outperforms a thick, badly ground knife in premium steel. The steel mainly determines how long that feeling lasts before sharpening.