If you've spent any time researching Japanese knives, you've seen the steel names: VG-10, Aogami, SG2, Shirogami. They appear on product pages with little explanation. This is a technical breakdown of what each steel actually does -- and why it matters for edge retention, sharpening, and long-term performance.
VG-10: The Workhorse
VG-10 is a stainless steel produced by Takefu Special Steel in Fukui Prefecture. The name stands for "V Gold 10" -- a proprietary alloy that Takefu has refined over decades.
The composition that makes it interesting:
- Carbon: ~1.0% (high enough for real hardness)
- Chromium: ~15% (stainless, rust-resistant)
- Cobalt: ~1.5% (improves hardenability, allows higher HRC)
- Vanadium: ~0.2% (fine carbide formation, edge stability)
Typical hardness: 60-61 HRC. That's hard enough to hold a 15-degree edge geometry -- the standard for Japanese kitchen knives -- without chipping under normal use.
Where you'll find it: KAI Shun Classic, Tojiro DP, most mid-range Japanese knives available in Europe. The Tojiro DP Gyuto is probably the most documented VG-10 knife on the market, with thousands of long-term user reviews confirming edge retention data that matches the spec sheet.
Aogami (Blue Steel): The Carbon Option
Aogami -- "blue paper steel" -- is produced by Hitachi Metals (now Proterial) in their Yasugi facility in Shimane Prefecture. It's a high-carbon, non-stainless steel. That distinction matters.
Two main variants:
Aogami #1:
- Carbon: 1.2-1.4%
- Chromium: 0.2-0.5% (not enough for stainless)
- Tungsten: 1.5-2.0% (wear resistance, edge stability)
- Typical HRC: 62-65
Aogami #2:
- Carbon: 1.0-1.2%
- Slightly less tungsten
- Typical HRC: 61-64
- More forgiving to sharpen, slightly less wear-resistant
Aogami #2 is the entry point for carbon steel Japanese knives. Aogami #1 is what craftsmen in Sakai use for professional yanagiba and deba -- blades that need to hold a single-bevel edge at 8-10 degrees through a full shift.
The trade-off: carbon steel reacts. Aogami will patinate, and if left wet, it will rust. For the right user -- someone who wipes the blade after each cut -- it's the highest-performing option at any price point.
SG2 (Super Gold 2): Powder Metallurgy
SG2 is where the metallurgy gets interesting. Produced by Takefu Special Steel, it's a powder metallurgy steel -- the alloy is atomized into powder before sintering, which produces a microstructure that's impossible to achieve with conventional casting.
The result: extremely fine, uniformly distributed carbides. In practical terms:
- Carbon: ~1.45%
- Chromium: ~14-16% (fully stainless)
- Typical HRC: 62-65
- Edge stability comparable to Aogami #1, with stainless corrosion resistance
Where you'll find it: Miyabi 5000MCD, some Global SAI models. It's expensive to produce -- the powder metallurgy process adds cost at every stage. But for a stainless steel that performs at the level of high-carbon, there's no better option in production knives.
How They Compare
| Steel | HRC | Stainless | Sharpening | Edge Life | Produced by |
|---|---|---|---|---|---|
| VG-10 | 60-61 | Yes | Medium | Good | Takefu, Fukui |
| Aogami #2 | 61-64 | No | Easy | Very good | Hitachi, Shimane |
| Aogami #1 | 62-65 | No | Medium | Excellent | Hitachi, Shimane |
| SG2 | 62-65 | Yes | Medium-hard | Excellent | Takefu, Fukui |
What This Means in Practice
The steel choice isn't just a spec -- it determines the maintenance routine, the sharpening equipment you need, and how the knife performs over years.
VG-10 is the most practical entry point: stainless, predictable, widely available in knives with solid geometry. Aogami #2 is the next step if you're comfortable with carbon steel maintenance and want higher peak sharpness. SG2 is for when you want Aogami-level performance without the rust risk -- and you're willing to pay for it.
For a deeper breakdown of which knives use each steel -- with real availability data and long-term user analysis -- the full guide is at hamonoclub.com/aceros-japoneses-vg10-aus10-sg2-aogami/.
Hamono Club is an independent editorial on Japanese knives. No manufacturer relationships -- just steel, geometry, and honest analysis.
Top comments (0)