1. Product Type Standards Fasteners: Compliant with DIN/IFI/JIS/ISO standards, covering core automotive products such as shoulder bolts, gear bars, spline screws, truck bolts, four-cornered screws, carriage screws, and T-bolts; chassis components, nuts, sleeves, exhaust pipe hooks, safety belt mandrel parts, and assemblies. Other products: rivets, irregular parts, customized products, mold-closing screws, special screws, and double bolts. 2. Product Specifications and Material Specifications: IFI standard (NO.4–1 inch, maximum length 8 inches), DIN standard (M4–M24, maximum length 200mm). Materials: carbon steel (compliant with ISO-898 and SAE J-429 standards), alloy steel, copper, aluminum alloy, and stainless steel (A2-50, A2-70, etc.). 3. Surface treatments include electro-galvanizing (trivalent chromium, hexavalent chromium), alloy plating (zinc-iron alloy, zinc-nickel alloy), painting (GEOMET, MAGNI, DELTA-TONE, etc.), electroplating of tin/nickel/copper, zinc phosphate, hot-dip galvanizing, and mechanical galvanizing. 4. The anti-loosening design covers chassis components, nuts, sleeves, exhaust pipe suspensions, main shaft parts of seat belts, assemblies, and various fasteners including bolts and nuts, carbon steel screws, stainless steel screws, and bimetallic screws.