carbon · Hitachi Metals (now Proterial) · HRC 63-65

Aogami Super Steel: Blue Super Carbon Steel Explained

Aogami Super steel is Hitachi's top carbon steel at HRC 63-65. See how an Aogami Super knife cuts and sharpens, and how it compares with Aogami 2 and SG2.

At a glance

Edge retentionEase of sharpeningRust resistanceToughness (chip resistance)

Relative to the other steels on this site. Hardness 63-65 Rockwell C as typically heat treated.

Aogami Super, also sold as Blue Super, is the top grade of Hitachi’s blue paper carbon steels. Hitachi Metals was renamed Proterial in 2023, but knife makers and buyers still use the old names. Among carbon steels in Japanese kitchen knives, it is the one chosen for maximum edge life.

What Aogami Super steel is

Aogami steels start from the same very clean high-carbon steel as Shirogami, then add chromium and tungsten. The additions form hard carbides that help the edge last. Aogami Super has the most carbon and the most alloy in the family, and makers usually harden it to HRC 63 to 65. It is carbon steel, not stainless, so it reacts with water and acidic food.

How an Aogami Super knife behaves

Edge retention is high, close to SG2 and well above VG-10. It takes a very keen edge and still sharpens more easily than the powder stainless steels, with a clean, crisp burr on water stones. At full hardness it can chip if twisted or used on bone. It will rust. Expect a patina to form within days, shifting from blue gray to darker tones as you cook.

Who makes Aogami Super knives

Moritaka Hamono in Kumamoto forges it into rustic kurouchi blades like the Moritaka Aogami Super bunka. Echizen smiths, including Kurosaki, use it in forged lines, and Tosa blacksmiths in Kochi offer it in their rougher kurouchi styles. Prices for a gyuto or bunka usually land between $150 and $350 and move with the yen. Learn more in our regions guide.

Aogami Super vs Aogami 2 and SG2

Steel Type Typical HRC Edge retention Rust
Aogami 2 Carbon 61-63 Middle Rusts
Aogami Super Carbon 63-65 High Rusts
SG2/R2 Powder stainless 62-64 High Resists

Aogami Super vs Aogami 2 is a tradeoff between edge life and toughness. Aogami 2 is a little more forgiving and quicker to sharpen, and Aogami Super lasts longer between sessions. Aogami Super vs SG2 is carbon against stainless at similar edge life. Aogami Super feels keener and sharpens faster, and SG2 lets you skip patina and rust care.

Who should buy Aogami Super

It suits cooks who like carbon steel, dry their knives as a habit, and want the longest edge life that carbon offers. A bunka or gyuto in Aogami Super is a common second Japanese knife after a stainless starter.

Maintenance

Wipe it while you cook, especially after onions, citrus, or tomatoes. Wash, dry fully, and store dry. A thin coat of camellia or mineral oil helps before long storage. If orange rust appears, a rust eraser or fine abrasive removes it. Our carbon steel care guide goes into detail.

Downsides

It rusts, it reacts with food, and a new blade can leave a metallic smell on onions until the patina forms. The high hardness makes it more chip prone than Aogami 2 or Shirogami 2. Kurouchi finishes also vary from maker to maker, and some cooks find the rough finish sticks to food.

If you want an Aogami Super knife and are unsure about shape or length, ask us which knife fits your cooking and we will quote it with duties prepaid.

Frequently asked questions

Is Aogami Super stainless?

No. It is a carbon steel and will rust if left wet. Most Aogami Super knives are clad in softer iron or stainless, but the edge itself always needs drying.

Is Aogami Super better than Aogami 2?

It holds an edge longer and runs harder. Aogami 2 is a bit tougher and a bit easier to sharpen, so many cooks see them as equals with different strengths.

What does blue super mean?

Aogami means blue paper, after the colored paper Hitachi wraps the steel in. Super is the highest alloyed grade of the blue family.

Aogami Super knives in our catalog

All knives