440C steel is a high-carbon stainless steel that is commonly used in the production of knife blades. It is part of the 440 series of stainless steels, which includes 440A, 440B, and 440C.

Here are some key characteristics of 440C steel:

1. Composition: 440C steel contains approximately 1.0% carbon, 17% chromium, 1.0% manganese, 0.75% molybdenum, and varying amounts of other elements such as silicon and phosphorus. The high carbon and chromium content contribute to its excellent hardness, corrosion resistance, and wear resistance.
2. Hardness: 440C steel can be hardened to achieve high levels of hardness. It typically has a hardness range of 58-62 HRC (Rockwell hardness scale), making it one of the harder stainless steels available. The high hardness allows 440C steel to hold a sharp edge well.
3. Wear Resistance: 440C steel is known for its excellent wear resistance, making it suitable for applications where the blade needs to maintain cutting performance for extended periods. It can withstand abrasive materials and heavy use without significant edge dulling.
4. Corrosion Resistance: 440C steel is a stainless steel and offers good corrosion resistance compared to many other high-carbon steels. However, it is not as corrosion-resistant as some other stainless steels with higher chromium content. Proper care, cleaning, and maintenance are still important to prevent rust and staining.
5. Toughness: 440C steel exhibits good toughness, which allows it to withstand impacts and resist chipping or breaking. It offers a good balance between hardness and toughness.

440C steel is a popular choice among knife makers and enthusiasts due to its combination of hardness, wear resistance, and corrosion resistance. It is commonly used in the production of high-end and performance-oriented knives where edge retention and durability are desired. Its stainless nature also makes it more resistant to corrosion compared to non-stainless high-carbon steels.