What are the quality standards for self tapping nails?

The quality standards for self tapping nails mainly include the following aspects:

1、 Appearance quality

Head shape: The head of a self tapping nail should be regular, without obvious cracks, scratches, or deformations.

Surface smoothness: The surface of self tapping nails should be smooth and free of cracks, scratches, and unevenness.

Surface paint film: The surface of self tapping nails should be coated with anti-corrosion paint, and the paint film should be uniform, free of bubbles, peeling, and cracking.

Rust: Self tapping screws should not show obvious rust or corrosion, and the rusted area should not exceed 15% of the screw diameter, and the maximum depth should not exceed 5% of the thread height.

2、 Size quality

Diameter: The diameter of self tapping nails should comply with the established national standards.

Length: The length of the self tapping nail should match the required project.

Thread specifications: The thread specifications should also comply with the established national standards.

Joint part: must not deform, maintain good mutual adaptation conditions, and the conical clamping mouth must not deform.

Pressure head part: must be full, with clear cutting rules, and there must be no defects such as burrs or cracks that affect the durability of the thread at the cutting point.

3、 Material quality

Material: The material of self tapping screws must comply with national standards, have a uniform texture, and be free of defects such as pores, cracks, scars, and inclusions.

Aperture: It must comply with the design regulations and the opening conditions of the board must meet the requirements.

Electrochemical corrosion: The material of self tapping screws is the same or similar to that of sheet metal, and electrochemical corrosion between different metals must not occur.

4、 Mechanical performance requirements

Tensile strength: The tensile strength shall not be less than 0.8 Valent/square millimeter.

Hardness: The hardness shall not be less than 150HV, and the specific hardness level may vary depending on the purpose and material, such as the common Rockwell hardness standards HRC45-HRC55, HRC55-HRC62, etc.

Impact strength: The impact test conducted under specific conditions did not show any brittle cracking phenomenon.

The above are the main quality standards for self tapping screws. Manufacturers and manufacturers should strictly adhere to these standards to ensure that the produced self tapping screws are of qualified quality, safe and reliable, and can meet customer needs. Meanwhile, these quality standards are also important criteria for evaluating the performance and effectiveness of self tapping screws.