GB/T90.1-2023 Standard fasteners – Acceptance inspection

GB/T90.1-2023 Standard Fastener Acceptance Inspection

The GB/T90.1-2023 standard incorporates modifications based on ISO 3269-2019, focusing on the acceptance inspection of fasteners.

This updated standard replaces GB/T 90.1-2002, featuring significant technical changes outlined below:

Key Changes in GB/T 90.1-2023

• Definition of Inspection Lot: The definition now includes fasteners that share the same production batch number.
• Acceptance Sampling Method: The method based on Ac=0 for small samples has been revised (refer to Table 1 and Appendix A in the 2023 version).
• Sample Size Requirements: Now determined based on the size of the lot (see Table 1 and Appendix A in the 2023 version).
• Inspection Categories for Threaded Components: New categories have been added for measuring the major diameter of external threaded parts and the minor diameter of internal threaded parts (see Table 2).
• Arbitration Method in Case of Disagreement: An arbitration method for resolution has been introduced if an agreement cannot be reached.

Refer to the original source for detailed tables, which outline the sampling sizes, acceptance numbers (Ac), and rejection numbers (Re) for various lot sizes. The first, second, and third categories relate to different properties and criteria for acceptance, with specific testing methods required for mechanical and physical properties, size characteristics, and functional characteristics.

Understanding the Categories

Category 1: Mechanical and Functional Properties

This category includes critical mechanical properties assessed through destructive testing. Any non-conformance found in the samples leads to the rejection of the lot, and further actions must be taken as described in the standard.

Category 2: Major Dimension Characteristics

For characteristics that could impact assembly or functionality, a second sampling is permissible if initial tests reveal non-conformance. If the second sample meets the criteria, the lot can be accepted; otherwise, it will be subjected to rejection protocols.

Category 3: Minor Dimension Characteristics

This category allows for minor non-conformances in certain functional characteristics. However, if the number of non-conformances exceeds the established limit, the lot must be rejected, and appropriate measures must be followed as per the standards.

While the detailed tables are not included here, they specify various inspection categories for fastener characteristics, covering mechanical properties, dimensional features, and functional aspects. Each characteristic has specific testing requirements and acceptance criteria, ensuring that fasteners meet the necessary performance standards.