This comprehensive guide compares the three popular pocket knife blade materials: 440C stainless steel, D2 tool steel, and Damascus steel. 440C excels in corrosion resistance and is great for everyday and wet environments. D2 offers superior edge retention and toughness for heavy-duty use but requires more maintenance. Damascus steel is unique and decorative, combining layered steels for balanced performance but demanding care. Choosing the best steel depends on your usage needs, maintenance willingness, and budget.