National standard bolts refer to bolt products that meet national standards and are designed for easy use and reliable performance. Their size specifications are formulated by the national standardization authority, ensuring consistency and applicability in various engineering scenarios.
Among them, the GB/T 5780-2000 standard applies to hexagon head bolts (full thread), with specifications ranging from M5 to M64 and a length range of 10mm to 200mm. The GB/T 5782-2000 standard applies to hexagon head bolts (half thread), with the same specification range as the GB/T 5780-2000 standard.
High-strength socket head cap screws generally adopt the GB/T 70.1-2000 standard, with specifications ranging from M12 to M30 and a length range of 35mm to 200mm. Ordinary bolts usually adopt the GB/T 3098.1-2010 standard (this standard is a mechanical performance standard for bolts, and the supporting dimensional standard can refer to GB/T 5780, etc.), with specifications ranging from M6 to M64 and a length range of 12mm to 200mm.
It should be noted that the above are only common standards related to the size specifications of national standard bolts. In practical applications, there are more subdivided standards and size specifications available. In specific use, the appropriate bolt specification shall be selected in strict accordance with the engineering design requirements.
In addition to the common Chinese national standard bolt size specifications, there are various commonly used international bolt standards, such as the German DIN standard, the international ISO standard, and the American ANSI standard. Each of these standards has its specific purpose and scope of application.
The DIN standard is formulated by the German Institute for Standardization. Among them, DIN 931 (hexagon head bolt, half thread) and DIN 933 (hexagon head bolt, full thread) are the most common hexagon head bolt standards, with size specifications ranging from M1.6 to M64 and a length range of 2mm to 600mm.
The ISO standard is formulated by the International Organization for Standardization. Among them, ISO 4014 (hexagon head bolt, full thread) and ISO 4017 (hexagon head bolt, half thread) are commonly used hexagon head bolt standards, with size specifications ranging from M1.6 to M64 and a length range of 2mm to 600mm.
The ANSI standard is formulated by the American National Standards Institute. Among them, ANSI B18.2.1 is a common hexagon head bolt standard, with size specifications ranging from #6 to 4 inches and a length range of 1/4 inch to 20 inches (Note: The ANSI standard adopts imperial units).
The above various standards include various types of bolts, such as hexagon head bolts, studs, and screws, each with corresponding size specification tables. When selecting bolts, the appropriate standard and specification shall be selected according to specific needs, load-bearing requirements, and application scenarios.
In addition to the above standards, there are commonly used standards such as the Japanese JIS (Japanese Industrial Standards) and British BS (British Standards), each with its specific application scenarios and purposes.
It should be noted that different countries or regions usually have their own bolt standards. Therefore, when selecting bolts, the standard requirements of the corresponding region shall be given priority. If it involves product import or export, the bolt standards of the target country or region shall be strictly followed to ensure product adaptability.
JIS (Japanese Industrial Standards) is formulated by the Japanese industrial standardization organization. Among them, JIS B1180 and JIS B1181 are commonly used hexagon head bolt standards, applicable to bolts with diameters from M5 to M64 and a length range of 10mm to 600mm.
BS (British Standards) is formulated by the British standardization organization. Among them, BS 4190 and BS 3692 are common hexagon head bolt standards, applicable to bolts with diameters from M1.6 to M64 and a length range of 2mm to 600mm.
Various bolt standards clearly specify the requirements for bolt size, purpose, material, mechanical performance, etc., providing a unified basis for bolt manufacturing, inspection, and use, and ensuring application standardization. It should be particularly noted that when selecting bolts with reference to the standard specification table, the specific application scenario and actual needs must be considered; at the same time, it is necessary to ensure that the selected bolts meet the relevant quality and safety standards to avoid equipment damage or potential safety hazards caused by inconsistent specifications or substandard quality.
