(1) Comprehensive Testing: After batch production is completed, 100% visual inspection of all products + 10% dimensional sampling inspection. Core items (threads, dimensions, coating) are 100% fully inspected.

(2) Appearance Quality: No burrs, oxidation, rust, or scratches; surface finish meets requirements. Hot-dip galvanized parts have uniform zinc coating with no missing spots.

(3) Dimensional Accuracy: Thread specifications (metric / imperial / US), length, diameter, head dimensions, chamfer, etc.

(4) Fit Testing: Verifies the compatibility between finished bolts and nuts.

(5) Mechanical Properties: Tensile strength, yield strength, hardness – conforming to corresponding grade standards.

(6) Coating Quality: Salt spray testing, adhesion testing.

(7) Marking and Labeling: Product markings are clear (specifications, grade, standard number, manufacturer mark). Packaging labeling complies with export customs and customer requirements.