Chinese National Standards For Hot-Dip Galvanized Bolts

Hot-dip galvanized bolts are fasteners subjected to special processing and surface treatment, featuring excellent oxidation resistance, corrosion resistance, and humidity resistance. They are widely used in construction, machinery, electrical engineering, and other industries. During the production, inspection, and application of hot-dip galvanized bolts, strict compliance with Chinese national standards is required to guarantee product quality, performance, and operational safety.

National standards serve as the core basis for evaluating the quality and performance of hot-dip galvanized bolts. The relevant standards are explained in detail from five key aspects below:

1. Thread Tolerance Standards

Precise control of thread tolerances is critical in the production of hot-dip galvanized bolts, as it directly determines the fitting accuracy and connection reliability between bolts and nuts. GB/T 90.1-2002 Fasteners - Tolerances for Threads specifies the values and allowable deviations of thread tolerances, providing a clear basis for thread manufacturing quality and ensuring thread dimensions meet design requirements for tight and stable connections.

2. Thread Inspection Standards

Thread inspection is a key step in quality control for hot-dip galvanized bolts, allowing accurate judgment of whether thread quality conforms to standards. GB/T 90.2-2002 Fasteners - Inspection of Threads defines inspection methods, tools, and acceptance criteria for bolt threads, including visual inspection, dimensional inspection, and thread accuracy inspection. These standardized procedures ensure the accuracy, integrity, and conformity of threads.

3. Hot-Dip Galvanized Coating Standards

Hot-dip galvanizing is a core process in manufacturing galvanized bolts, providing long-term corrosion and wear protection to extend service life. GB/T 5267.1-2019 Fasteners - Hot-Dip Galvanized Coatings (upgraded from GB/T 5267.1-2012) specifies requirements for coating quality, chemical composition, appearance, and adhesion, effectively ensuring stable performance and reliable corrosion protection of the zinc coating.

4. Mechanical Property Class Standards

Mechanical properties are core indicators of bolt quality, directly related to load capacity, pull-out resistance, shear resistance, and safety. GB/T 3098.15-2019 Fasteners - Mechanical Properties - Hot-Dip Galvanized Bolts, Screws, Studs and Nuts (upgraded from GB/T 3098.15-2010) defines mechanical property classes, including tensile strength, yield strength, hardness, and impact toughness, providing clear criteria for evaluating mechanical performance and reliability.

5. Coating Thickness Measurement Standards

The thickness of the hot-dip galvanized coating is a key parameter determining corrosion resistance and service life. Non-conforming thickness directly weakens anti-corrosion performance. GB/T 9445-2015 Metallic Coatings - Hot-Dip Galvanized Coatings - Specifications and Test Methods (upgraded from GB/T 9445-2008) specifies measurement methods, allowable deviations, and acceptance rules for coating thickness, ensuring accurate and reliable test results.

In summary, Chinese national standards for hot-dip galvanizing are important guidelines for the production, inspection and application of hot-dip galvanized bolts. Only by strictly complying with relevant standard requirements can we manufacture high-quality hot-dip galvanized bolts and enhance product competitiveness and market share.

For this reason, Jinrui attaches great importance to the implementation of standards, strengthens quality control throughout the entire production process, conducts inspections strictly in accordance with standards, and continuously improves product quality and performance to ensure that our products meet the safe application requirements of various scenarios.

If you need hot-dip galvanized bolts or other solutions for hot-dip galvanized products, you are welcome to contact us for consultation.