The price is primarily driven by material grade, surface treatment, and dimensional precision. For instance, Stainless Steel 316 commands a higher price than SS304 or Carbon Steel due to its superior corrosion resistance. Additionally, high-strength fasteners (e.g., Grade 8.8, 10.9, or 12.9) require specialized heat treatment, increasing the cost compared to standard Grade 4.8. Surface coatings like Hot-Dip Galvanizing (HDG) or Zinc-Nickel plating also add to the unit price but are essential for outdoor or industrial longevity.