D2 steel is a high-carbon, high-chromium tool steel known for its excellent wear resistance and toughness. It belongs to the family of air-hardening tool steels and is widely used in the production of knives, cutting tools, and industrial blades.

Here are some key characteristics of D2 steel:

1. Composition: D2 steel typically contains approximately 1.5% carbon, 12% chromium, 0.8% molybdenum, 0.9% vanadium, and varying amounts of other elements such as silicon and manganese. The high carbon content contributes to its hardness and edge retention, while the chromium provides excellent wear resistance and corrosion resistance.
2. Hardness: D2 steel can achieve high levels of hardness through proper heat treatment. It typically has a hardness range of 58-62 HRC (Rockwell hardness scale), making it one of the harder tool steels available. The high hardness allows D2 steel to retain a sharp edge for extended periods of use.
3. Wear Resistance: D2 steel is known for its exceptional wear resistance. It can withstand abrasive materials, heavy use, and high-impact applications without significant loss of edge sharpness. This property makes D2 steel suitable for applications where the blade needs to maintain cutting performance for extended periods.
4. Toughness: Along with its wear resistance, D2 steel exhibits good toughness, allowing it to withstand impacts and resist chipping or breaking. This combination of hardness and toughness makes D2 steel a popular choice for blades subjected to demanding cutting tasks.
5. Corrosion Resistance: While D2 steel has good resistance to wear, it is not considered stainless. It is not as corrosion-resistant as stainless steels, and proper care should be taken to prevent rust and corrosion. Regular cleaning, drying, and oiling are recommended to maintain the blade's condition.

D2 steel is favored by many knife makers and tool users for its balance of hardness, wear resistance, and toughness. It is commonly used in the manufacturing of high-end and performance-oriented knives, industrial blades, and cutting tools. However, its non-stainless nature requires appropriate care to prevent rusting and staining.