AUS-6 (also known as AUS-6M) is a Japanese stainless steel produced by Aichi Steel. In the hierarchy of Japanese steels, it is an entry-level grade, comparable to the American 420 series or the Chinese 3Cr13/6Cr13 series.
While it was very popular in the 1990s and early 2000s for affordable knives, it has largely been replaced in modern folders by higher-carbon steels like 8Cr13MoV or AUS-8.
Key Characteristics
High Corrosion Resistance: This is its strongest attribute. With a high chromium-to-carbon ratio, it is very resistant to rust and staining, making it suitable for wet environments.
Excellent Toughness: Because it is a "softer" steel, it is very difficult to chip or break. It is flexible and can handle high impact.
Ease of Sharpening: It is incredibly easy to sharpen. You can get a very keen edge on AUS-6 with minimal effort, even with basic sharpening tools.
Lower Edge Retention: Due to its lower carbon content (around 0.6%), it does not stay sharp for long compared to premium steels. It is typically hardened to 55–57 HRC.
Chemical Composition
Carbon (C): 0.55% – 0.65% (Provides moderate hardness)
Chromium (Cr): 13.0% – 14.5% (Provides rust resistance)
Manganese (Mn): 1.0%
Vanadium (V): 0.10% – 0.25% (Small amount to help with grain refinement and toughness)
Common Applications
Entry-Level Folding Knives: Formerly a staple for brands like SOG, Spyderco (in their older budget lines), and Cold Steel.
Kitchen Cutlery: Used for household knives where ease of sharpening and rust resistance are more important than long-term edge holding.
Diving & Fishing Knives: Where constant exposure to water is a concern.
Budget Multi-tools: Used for secondary blades or tools.
The AUS Series Comparison
Steel | Carbon Content | Performance Level |
|---|---|---|
AUS-6 | ~0.6% | Entry-level / High Toughness |
AUS-8 | ~0.75% | Mid-range / Best-selling balance |
AUS-10 | ~1.0% |