Carbon steel · ProterialAogami Super 青紙スーパー
Also called: Blue Super · Ao Super · Aogami Super Blue
Aogami Super is a non-stainless carbon steel from Proterial (formerly Hitachi Metals): 1.40–1.50% carbon, 0.30–0.50% chromium, and a maker hardening hardness of ≥60 HRC. In Knife Steel Nerds’ CATRA edge-retention test it cut 338 mm of card at 65.1 HRC.
Composition
| C | Si | Mn | P | S | Cr | W | V |
|---|---|---|---|---|---|---|---|
| 1.40–1.50 | 0.10–0.20 | 0.20–0.30 | ≤0.025 | ≤0.004 | 0.30–0.50 | 2.00–2.50 | 0.30–0.50 |
Mass %. As published by the steelmaker (typical or representative values). Hardness: ≥60 (hardening hardness).
What the data says
Aogami Super has the most carbon of Proterial’s paper steels — 1.40–1.50% — together with 2.00–2.50% tungsten, 0.30–0.50% chromium and 0.30–0.50% vanadium. Proterial does not list molybdenum for it; some retailers say it contains molybdenum but give no figure.
In Knife Steel Nerds’ tests it reached 65.1 HRC and cut 338 mm of card in the CATRA edge-retention test, and the site describes Blue Super as having higher edge retention but relatively low toughness.
In Knife Steel Nerds’ CATRA test, which measures how much abrasive card an edge can cut, steels with more hard carbides (from chromium, vanadium or tungsten) generally cut more card than simple carbon steels, even at the same or higher hardness. That is why stainless steels such as VG-10 (479 mm at 61.6 HRC) and SG2 (522 mm at 61.2 HRC) scored higher in the same test.
Proterial’s published hardening hardness is “60 HRC or over”; hardness figures above that, which you will see quoted by shops, describe particular knifemakers’ heat treatments rather than the steel’s specification.
Aogami Super compared with similar steels
| Steel | Type | C % | Cr % | Maker HRC | CATRA mm |
|---|---|---|---|---|---|
| Aogami Super | Carbon | 1.40–1.50 | 0.30–0.50 | ≥60 | 338 @ 65.1 |
| Aogami #2 | Carbon | 1.05–1.15 | 0.20–0.50 | ≥60 | — |
| SG2 (Super Gold 2) | Powder stainless · PM | 1.25–1.45 † | 14.0–16.0 † | ≥62 | 522 @ 61.2 |
| VG-10 | Stainless | 1.00 | 15.00 | ≥60 | 479 @ 61.6 |
Detailed comparisons: Blue vs White steel · Aogami Super vs SG2
See all 15 steels in the Japanese knife steel chart, or compare up to three at once in the steel explorer.
Care
Aogami Super is not stainless. Wipe the blade dry after use; a grey or blue patina is normal, but orange spots are rust and should be removed early.
Buying a Aogami Super knife from a shop in Japan? Japanese kitchen knives currently pay about 31% US import duty — use the import duty calculator to compare with a US retailer.
Frequently asked questions
- Is Aogami Super stainless?
- No. Aogami Super contains only 0.30–0.50% chromium, while a stainless steel needs roughly 10.5% or more, so it can rust if left wet.
- How hard is Aogami Super?
- Proterial publishes a hardening hardness of ≥60 HRC. The hardness of a finished knife depends on the knifemaker’s heat treatment.
- Who makes Aogami Super?
- Aogami Super is made by Proterial (formerly Hitachi Metals).
- Aogami Super vs Aogami #2: what is the difference?
- Aogami Super: C 1.40–1.50%, Cr 0.30–0.50%, maker hardness ≥60 HRC. Aogami #2: C 1.05–1.15%, Cr 0.20–0.50%, maker hardness ≥60 HRC.
Sources
- Proterial grade page
- Knife Steel Nerds: edge retention of 48 steels (secondary)
- Knife Steel Nerds: is Blue Super actually super? (secondary)
Checked 2026-10-21. Found a better source or an error? Tell us.