Steel chart · maker data checked 2026-10-21Japanese knife steel chart
15 steels, one table. Every composition and hardness value below comes from the steelmaker’s own published data — Proterial (formerly Hitachi Metals), Takefu Special Steel and Aichi Steel — except where marked †. Tap a column to sort, or filter by type.
| Steel | Maker | Type | C % | Cr % | Other | Maker HRC | CATRA mm |
|---|---|---|---|---|---|---|---|
| Shirogami #1 白紙1号 | Proterial | Carbon | 1.25–1.35 | — | — | ≥60 | — |
| Shirogami #2 白紙2号 | Proterial | Carbon | 1.05–1.15 | — | — | ≥60 | — |
| Shirogami #3 白紙3号 | Proterial | Carbon | 0.80–0.90 | — | — | ≥60 water-quenched; ≥52 oil-quenched and tempered at 280–340 °C | — |
| Aogami #1 青紙1号 | Proterial | Carbon | 1.25–1.35 | 0.30–0.50 | W 1.50–2.00 | ≥60 | — |
| Aogami #2 青紙2号 | Proterial | Carbon | 1.05–1.15 | 0.20–0.50 | W 1.00–1.50 | ≥60 | — |
| Aogami Super 青紙スーパー | Proterial | Carbon | 1.40–1.50 | 0.30–0.50 | W 2.00–2.50, V 0.30–0.50 | ≥60 | 338 @ 65.1 |
| Ginsan (Silver #3) 銀紙3号 | Proterial | Stainless | 0.95–1.10 | 13.00–14.50 | — | ≥59 | — |
| VG-10 V金10号 | Takefu Special Steel | Stainless | 1.00 | 15.00 | Mo 1.00, V 0.25, Co 1.55 | ≥60 | 479 @ 61.6 |
| VG-1 V金1号 | Takefu Special Steel | Stainless | 1.00 | 14.00 | Mo 0.30 | ≥61 | — |
| SG2 (Super Gold 2) スーパーゴールド2 | Takefu Special Steel | Powder stainless · PM | 1.25–1.45 † | 14.0–16.0 † | Mo 2.3–3.3, V 1.8–2.2 | ≥62 | 522 @ 61.2 |
| ZDP-189 ZDP189 | Proterial | Powder stainless · PM | 3.00 | 20.00 | — | ≥65 | 718 @ 65.1 |
| HAP40 HAP40 | Proterial | Powder high-speed · PM | 1.27–1.37 | 3.70–4.70 | Mo 4.60–5.40, W 5.60–6.40, V 2.80–3.30, Co 7.50–8.50 | 64–66 or 66–68, depending on quench temperature | — |
| SLD (≈ D2 / SKD11) SLD | Proterial | Semi-stainless | 1.50 | 12.00 | Mo 0.90, V 0.30 | ≥58 | 486 @ 60.5 |
| AUS-8 AUS-8 | Aichi Steel | Stainless | 0.70–0.80 | 13.00–14.50 | Mo 0.10–0.30, V 0.10–0.25 | 59 (reference value) | — |
| AUS-10 AUS-10 | Aichi Steel | Stainless | 0.95–1.10 | 13.00–14.50 | Mo 0.10–0.30, V 0.10–0.25 | 60 (reference value) | — |
Compositions in mass %, typical or representative values as published. Maker HRC is the steelmaker’s hardening hardness (usually a minimum), not the hardness of a finished knife. CATRA: Knife Steel Nerds edge-retention test, total card cut in mm at the HRC shown (SLD tested as the equivalent AISI D2). † retailer values; Takefu does not publish the SG2 composition. PM = powder metallurgy.
How to read the chart
- Carbon (C) lets a steel be hardened. The White and Blue paper steels range from 0.80% (Shirogami #3) to 1.50% (Aogami Super); ZDP-189 has 3.00%.
- Chromium (Cr) is what makes a steel stainless; stainless steels contain at least about 10.5% chromium. The paper steels have none or under 0.5%, so they rust if left wet.
- Tungsten (W), molybdenum (Mo), vanadium (V) and cobalt (Co) are alloying additions. Proterial says the tungsten and chromium in the Blue steels improve heat-treatment properties and wear resistance.
- Maker HRC is the hardening hardness the steelmaker publishes. Shops often quote higher numbers; those describe a particular knifemaker’s heat treatment.
- CATRA is a machine test of how much abrasive card an edge can cut. Only some of these steels have been tested independently.
Compare steels side by side
- Blue vs White steel — Aogami (Blue) and Shirogami (White) steels share the same carbon levels; Blue adds 1.0–2.5% tungsten and a little chromium for wear resistance.
- Aogami Super vs SG2 — Aogami Super is a carbon steel that rusts; SG2 is a powder-metallurgy stainless.
- VG-10 vs SG2 — VG-10 and SG2 are both stainless steels from Takefu Special Steel.
Pick up to three steels in the steel explorer on the home page to see carbon, chromium, hardness and edge-retention bars next to each other. Buying from Japan? Check the import duty calculator first.
Frequently asked questions
- What is the difference between carbon and stainless Japanese knife steels?
- Stainless steels contain at least about 10.5% chromium, which lets them resist rust. Japanese carbon steels such as Shirogami and Aogami contain little or no chromium (Aogami has 0.2–0.5%), so they develop a patina and must be dried after use.
- What does HRC mean on a Japanese knife?
- HRC is the Rockwell C hardness scale. The figures on this page are the hardening hardness published by the steelmaker, usually a minimum. The hardness of a finished knife depends on the knifemaker’s heat treatment.
- Which Japanese knife steel holds an edge longest?
- Among the steels here tested by Knife Steel Nerds with the CATRA edge-retention test, ZDP-189 cut the most card (718 mm at 65.1 HRC), followed by SG2 (522 mm), D2/SLD (486 mm), VG-10 (479 mm) and Aogami Super (338 mm). Edge retention also depends on hardness, edge angle and what you cut.
- Is SG2 the same as R2?
- Shops commonly sell SG2 and R2 as the same powder stainless steel, but we could not confirm this from a primary source, and Takefu Special Steel does not publish the SG2 composition.