When sourcing PK knives, the blade steel grade is the most critical factor for performance. For budget-friendly options, look for 8Cr13MoV or 440C stainless steel, which offer decent corrosion resistance. For high-end professional markets, prioritize D2 tool steel, S35VN, or M390, which provide superior edge retention and hardness (58-62 HRC). Additionally, verify the handle material; G10, Micarta, or Carbon Fiber are preferred for their durability and non-slip grip properties compared to basic plastic.