SG2 / R2 vs Aogami Super SG2 / SPG2（粉末ハイス） / 青紙スーパー
Short answer
The two long-edge-life champions. Aogami Super is carbon (rusts, patinas, slightly easier to sharpen); SG2 is powder stainless (no rust, a bit harder to sharpen). Both are run very hard and both chip if abused.
| SG2 / R2 | Aogami Super | |
|---|---|---|
| Hardness (typical HRC) | 63–64 | 64–66 |
| Type | stainless | carbon |
| Easy to sharpen | ●●●●● | ●●●●● |
| Edge retention | ●●●●● | ●●●●● |
| Rust resistance | ●●●●● | ●●●●● |
| Chip resistance | ●●●●● | ●●●●● |
| Mark on the blade | SG2 / SPG2 / R2 / 粉末 | 青紙スーパー / 青スーパー / 特青 |
| Whetstone | 1000 → 3000–5000 | 1000 → 3000 (a diamond plate helps) |
Scores are relative, 1–5, for kitchen-knife use — our summary of maker data and common experience, not lab tests. Heat treatment and grind can move a knife a full point either way.
SG2 / R2 SG2 / SPG2（粉末ハイス）
Powder-metallurgy stainless. Long edge life, chips if abused. Kataoka's TAMAHAGANE and Kiryu's SPG2 line.
Who uses it: Kataoka Seisakusho, Kiryu Kogyo, Baba Hamono (Sakai), Hatsukokoro (Hyogo (brand)), Hitohira (Tokyo), Kato Yoshimi (Echizen (Takefu)), Konosuke (Sakai), Kurosaki Yu (Echizen (Takefu)), Miyabi (Seki), Nigara Hamono (Tsugaru (Aomori))
Sanjo examples with prices:
- Kataoka Seisakusho — TAMAHAGANE 響十 筋引 · ¥27,629
Aogami Super 青紙スーパー
Longest edge life of the Hitachi carbon steels. Kiryu Kogyo tempers it to HRC 64–65 inside stainless cladding.
Who uses it: Babacho Co., Hinoura Hamono Kobo, Kiryu Kogyo, Anryu Katsushige (Echizen (Takefu)), Fujiwara Teruyasu (Tokyo), Hatsukokoro (Hyogo (brand)), Kanehide (Seki), Kato Yoshimi (Echizen (Takefu)), Kurosaki Yu (Echizen (Takefu)), Moritaka Hamono (Kumamoto)
Sanjo examples with prices:
No Sanjo price rows yet.
Care
Wipe dry after use. Dishwasher still not recommended — the heat and detergent dull the edge and loosen handles.
Rinse and wipe dry immediately after each use — never leave it wet or in the sink.