When sourcing steel tie rods, you must focus on Material Grade (e.g., ASTM A36, 4140, or Stainless Steel 304/316) and Tensile Strength. The price is heavily influenced by the manufacturing process, such as hot-rolling versus cold-drawing, and the precision of thread cutting or rolling. Ensure the supplier provides Mill Test Certificates (MTC) to verify chemical composition and mechanical properties, as these directly impact the safety and longevity of the rods in structural or automotive applications.