Whether D2 steel is better than 440C steel depends on the specific requirements and priorities of the application. Both steels have their own advantages and trade-offs. Here's a comparison of D2 steel and 440C steel:

D2 Steel:

• Hardness and Edge Retention: D2 steel is known for its high hardness and excellent edge retention. It can achieve a higher level of hardness than 440C steel, typically ranging from 58-62 HRC. This allows D2 steel to hold a sharp edge for extended periods, making it well-suited for applications that demand excellent cutting performance.
• Wear Resistance: D2 steel offers exceptional wear resistance, allowing it to withstand abrasive materials and heavy use without significant edge dulling. It is a popular choice for blades subjected to demanding cutting tasks.
• Toughness: D2 steel exhibits good toughness, enabling it to resist chipping or breaking under impacts. However, it is not as tough as some other tool steels or stainless steels.
• Corrosion Resistance: D2 steel is not stainless and requires proper care to prevent rust and corrosion. While it offers some resistance to corrosion, it is not as corrosion-resistant as stainless steels like 440C.

440C Steel:

• Corrosion Resistance: 440C steel is a stainless steel and offers better corrosion resistance compared to D2 steel. It is more resistant to rust and staining, making it suitable for applications where moisture or exposure to corrosive environments is a concern.
• Toughness: 440C steel exhibits good toughness, allowing it to withstand impacts and resist chipping or breaking.
• Edge Retention: While 440C steel is known for its edge retention, it may not match the exceptional edge retention of D2 steel. However, it still offers good cutting performance and can maintain a sharp edge for a reasonable duration.

Both D2 steel and 440C steel have their merits and excel in different applications. D2 steel is often favored for its excellent hardness and wear resistance, making it suitable for heavy-duty cutting tasks. On the other hand, 440C steel is chosen for its better corrosion resistance and reasonable edge retention. Ultimately, the choice between D2 steel and 440C steel depends on the specific needs and priorities of the application, including factors such as expected use, maintenance requirements, and environmental conditions.