440B Steel is the "middle child" of the 440 series stainless steels. It sits between 440A (low carbon, high toughness) and 440C (high carbon, high hardness).
While it is less common today than 440C, it offers a specific balance for tools that need to be harder than 440A but tougher (less brittle) than 440C.
Key Characteristics
Balanced Hardness: It typically reaches a hardness of 56–58 HRC. This provides decent edge retention—better than the 420 series but not as long-lasting as 440C.
High Corrosion Resistance: Like all 440 series steels, it has a high chromium content, making it very resistant to rust and staining in wet conditions.
Good Toughness: Because it has less carbon than 440C, it is less brittle. This makes it more resistant to chipping when the blade hits a hard object.
Ease of Sharpening: It is relatively easy to sharpen compared to high-alloy "super steels," making it user-friendly for everyday maintenance.
Chemical Composition
The primary difference between 440A, B, and C is the Carbon content:
Carbon (C): 0.75% – 0.95% (Higher than 440A's 0.60%, but lower than 440C's 1.10%)
Chromium (Cr): 16.0% – 18.0% (High for excellent rust resistance)
Manganese (Mn): 1.0%
Silicon (Si): 1.0%
Common Applications
Mid-Range Cutlery: Used for kitchen knives that need to be "stainless" but hold a decent edge.
Daggers and Survival Knives: Where a balance of edge holding and the ability to withstand impact (toughness) is required.
Industrial Tools: Used for valve parts, steam nozzles, and structural parts that require moderate wear resistance and high corrosion resistance.