When sourcing screws, the price is primarily driven by material grade, coating technology, and precision standards. For instance, Stainless Steel 316 commands a higher price than Carbon Steel due to its superior corrosion resistance. You must verify the tensile strength (e.g., Grade 8.8, 10.9, or 12.9) and the type of surface treatment, such as Hot-Dip Galvanizing, Zinc Plating, or Dacromet coating, as these factors significantly impact both the unit cost and the product's lifespan in specific environments.