JB/T 58651.1-1999
Fastener Product Quality Grading — General Principles
紧固件产品质量分等 总则
Catalogue
前言 → 1 范围 → 2 引用标准 → 3 名词、术语及代号 → 4 检查项目与抽样方案 → 5 测试方法 → 6 缺陷等级与缺陷加权值的划分 → 7 单位缺陷分计算公式 → 8 产品批质量等级的评定 → 附录A 普通螺纹极限尺寸 Foreword → 1 Scope → 2 Normative References → 3 Terms, Definitions and Symbols → 4 Inspection Items and Sampling Plan → 5 Test Methods → 6 Classification of Defect Grades and Defect Weight Values → 7 Formula for Unit Defect Score → 8 Assessment of Product Lot Quality Grade → Annex A Limit Dimensions of Common Threads
Scope
This standard specifies the principles and methods for quality grading of various types of fastener products manufactured according to national standards and industry standards. Fastener products manufactured according to other standards may also refer to this standard for quality grading. This standard adopts three-level grading, namely superior product, first-grade product, and qualified product. This standard is applicable to single specification product lots accepted according to GB/T 90.
本标准规定了按国家标准及行业标准生产的各类紧固件产品进行质量分等的原则和方法。按其他标准生产的紧固件产品进行质量分等时亦可参照使用。本标准采用三级分等，即优等品、一等品、合格品。本标准适用于按GB/T 90 接收了的单一规格产品批。
Normative References
Keywords
Application Summary AI generated
Fastener manufacturers and quality inspection agencies use this standard to classify products such as bolts, nuts, and screws into quality grades. By calculating defect weight values and unit defect scores, products are categorized as superior, first-grade, or qualified, ensuring consistent quality evaluation. This standard provides a unified framework for fastener quality grading, enhancing product reliability and customer confidence.
紧固件制造商和质检机构使用本标准来对螺栓、螺母、螺钉等产品进行质量等级划分。通过缺陷加权值和单位缺陷分计算，将产品分为优等品、一等品和合格品，确保不同质量水平的产品得到合理评价。该标准为紧固件行业提供了统一的质量分等依据，有助于提升产品质量和用户信任。
AI Summary AI generated
This standard specifies principles and methods for quality grading of fastener products, adopting three levels (superior, first-grade, qualified) and applying to lots accepted per GB/T 90. It defines three defect grades (critical, major, minor) with weight values (100, 50, 10 points) and uses a unit defect score formula for grade assessment. Inspection covers dimensions, surface defects, and mechanical properties, with a uniform sample size of n=80 and mechanical test samples of n=8 or 20. The standard provides a unified quality evaluation system for the fastener industry.
本标准规定了紧固件产品质量分等的原则和方法，采用三级分等（优等品、一等品、合格品），适用于按GB/T 90接收的产品批。标准定义了致命、严重和一般三个缺陷等级，并赋予加权值（100、50、10分），通过单位缺陷分公式计算评定质量等级。检查项目包括尺寸、表面缺陷、机械性能等，抽样方案统一为n=80，机械性能试验样本为n=8或20。该标准为紧固件行业提供了统一的质量评价体系。
Key Sentences extracted from text
本标准规定了按国家标准及行业标准生产的各类紧固件产品进行质量分等的原则和方法。
本标准采用三级分等，即优等品、一等品、合格品。
本标准适用于按GB/T 90 接收了的单一规格产品批。
本标准分为致命缺陷（A）、严重缺陷（B）和一般缺陷（C）共三个等级。
本标准规定产品尺寸、表面缺陷和混杂品的检查样本一律为n=80；机械性能试验的样本为n=8 或（和）n=20；合格判定数Ac 则按GB/T 90 规定的合格质量水平（AQL）分别给出。
This standard specifies the principles and methods for quality grading of various types of fastener products manufactured according to national standards and industry standards.
This standard adopts three-level grading, namely superior product, first-grade product, and qualified product.
This standard is applicable to single specification product lots accepted according to GB/T 90.
This standard is divided into three grades: critical defect (A), major defect (B), and minor defect (C).
This standard specifies that the inspection sample size for product dimensions, surface defects, and mixed items is uniformly n=80; the sample size for mechanical performance tests is n=8 or (and) n=20; the acceptance number Ac is given according to the acceptable quality level (AQL) specified in GB/T 90.
Standard Timeline
Changes from replaced version:
- 对原标准进行了编辑性的修改
- 主要技术内容没有变化
- Editorial modifications were made to the original standard
- The main technical content remains unchanged