H1 Steel is a unique precipitation-hardened stainless steel produced by Myodo Metal in Japan. It is legendary in the knife industry for one specific reason: it is completely rust-proof.
It is one of the few steels that can be submerged in salt water for years without showing a single speck of corrosion.
Key Characteristics
True Corrosion Immunity: H1 does not contain carbon in the traditional sense; most of the carbon is replaced by Nitrogen. Because there is no carbon to react with the chromium, it cannot rust. It is the ultimate steel for maritime and saltwater environments.
Work-Hardening Property: Unlike most steels that are hardened by heat-treating, H1 hardens through mechanical stress (work-hardening). This means the edge becomes harder as it is ground and sharpened.
Differential Hardness: Because of work-hardening, the serrated versions of H1 knives are significantly harder (up to 65 HRC at the edge) and hold an edge much better than the plain-edge versions (typically 57–58 HRC).
Extreme Toughness: It is a relatively soft and "gummy" steel in the spine of the blade, making it almost impossible to snap. It will bend long before it breaks.
Poor Edge Retention (Plain Edge): The biggest drawback is that in a plain-edge configuration, H1 does not stay sharp very long compared to modern super steels.
Chemical Composition
Carbon (C): 0.15% (Extremely low)
Chromium (Cr): 14.00% – 16.00%
Nitrogen (N): 0.10% (The key element for hardness and rust immunity)
Nickel (Ni): 6.00% – 8.00% (Increases toughness and corrosion resistance)
Manganese (Mn): 2.00% [10]
Common Applications
Diving & Fishing Knives: It is the gold standard for anyone working on the ocean.
Spyderco Salt Series: This is the most famous application. Knives like the Spyderco Pacific Salt and Tasman Salt were built around this steel.
Emergency Rescue Tools: Used for shears and hooks that must perform in wet, salty environments without maintenance.
H1 vs. LC200N
In recent years, LC200N has largely replaced H1 in many knives because LC200N is also rust-proof but offers much better edge retention in plain-edge blades.