The Chinese national standards for fasteners have recently undergone a significant update, particularly with the release of a batch of new standards on October 31, 2025. Most of these standards will be implemented starting from February 1, 2026. Below are the latest national standard versions and core specification information for commonly used fasteners:
1. Hexagonal head bolt (latest version)
The standards for the dimensions and tolerances of hexagon head bolts were comprehensively updated in 2025, replacing the previous 2016 version:
GB/T 5780-2025: Hexagon Head Bolts – Product Grade C (replacing GB/T 5780-2016, implemented on February 1, 2026)
GB/T 5781-2025: Hexagon Head Bolts – Full Thread – Product Grade C (replacing GB/T 5781-2016, implemented on February 1, 2026)
GB/T 5782-2025: Hexagon Head Bolts (replacing GB/T 5782-2016, implemented on February 1, 2026)
GB/T 5783-2025: Hexagon Head Bolts – Full Thread (replacing GB/T 5783-2016, implemented on February 1, 2026)
GB/T 5784-2025: Hexagon Head Bolts – Thin Shank, Grade B (replacing GB/T 5784-1986, implemented on February 1, 2026)
GB/T 5785-2025: Hexagon Head Bolts – Fine Pitch Thread (replacing the old version, implemented on 2026-02-01)
Common specification range: The thread specifications (diameter d) of hexagon head bolts typically cover M5 to M36 (or even larger up to M64, depending on the specific product grade), with a nominal length L ranging from approximately 8mm to 300mm.
2. Nut (latest version)
GB/T 3098.2-2025: Mechanical Properties of Fasteners – Part 2: Nuts (replacing the old version, implemented on February 1, 2026)
GB/T 6170-XXXX: Type I Hexagon Nuts, Grades A/B (Currently, the prevailing versions are mostly 2000/2015/2016, and the latest announcement needs to be verified)
GB/T 41-XXXX: Type I Hex Nut, Grade C
GB/T 3098.15-2023: Mechanical Properties of Fasteners – Stainless Steel Nuts (Current Version)
Common specification range: Hex nuts generally correspond to bolt specifications, commonly ranging from M5 to M48 or even wider.
3. Gasket (latest version)
GB/T 859-2025: Fasteners – Spring Washers – Light Duty (Implemented on February 1, 2026)
GB/T 3098.26-2021: Mechanical Properties of Fasteners – Plain Washers (Current Version)
GB/T 97.1 / GB/T 97.2: Plain Washers (Currently mostly in the 2002 version)
Common specification range: Flat washers and spring washers typically correspond to thread diameters ranging from d=2mm to 48mm.
4. Other commonly used fastener standards
Stud/Screw: GB/T 15389-2025 Fasteners – Screws (implemented on February 1, 2026, replacing the 1994 version); double-headed studs commonly have a diameter of d=M5 to M42.
Screw: GB/T 3098.5-2025 Self-tapping screw mechanical properties (implemented on 2026-02-01); common machine screws have diameters ranging from M2 to M10.
Basic/General Standard: GB/T 5276-2015 Fasteners – Bolts, Screws, Studs and Nuts – Dimensional Designation and Marking (Current Version).
Note: The above list includes the latest key standards that have been retrieved. Due to frequent updates of national standards, it is recommended to log in to the “National Standard Information Public Service Platform” or the “National Standard Full-Text Open System” during specific procurement or design, and enter the specific standard number (such as GB/T 5782) to check the real-time status to ensure that the currently valid version is being used.