JB/T 54254-1999
Product Quality Grading for Measuring Tools and Instruments - External Micrometer
量具量仪产品质量分等 外径千分尺
Catalogue
前言 → 1 范围 → 2 引用标准 → 3 合格品 → 4 一等品 → 5 优等品 → 6 等级评定 Foreword → 1 Scope → 2 Normative References → 3 Qualified Product → 4 First-Class Product → 5 Premium Product → 6 Grade Evaluation
Scope
This standard specifies the quality indicators for qualified products, first-class products, and premium products of external micrometers (hereinafter referred to as micrometers) with a graduation value of 0.01 mm, a micrometer screw pitch of 0.5 mm, a range of 25 mm, and a maximum measuring range of 0~1000 mm. This standard is applicable to the batch inspection and periodic inspection quality grade evaluation of micrometers produced in batches.
本标准规定了分度值为0.01 mm，测微螺杆螺距为0.5mm，量程为25 mm，测量范围最大为0~1000 mm 外径千分尺（以下简称千分尺）的合格品、一等品和优等品的各项质量指标。本标准适用于成批生产的千分尺逐批检查、周期检查质量等级的评定。
Normative References
Keywords
Application Summary AI generated
This standard is primarily used by quality inspectors in the machinery manufacturing and metrology industries to evaluate the quality grades of batch-produced external micrometers. By defining specific indicators for qualified, first-class, and premium products, it ensures the accuracy and reliability of micrometers, thereby safeguarding measurement precision. It is important for improving product quality and standardizing market practices.
这个标准主要用于机械制造和计量检测行业，帮助质检人员对成批生产的外径千分尺进行质量等级评定。它通过设定合格品、一等品和优等品的具体指标，确保千分尺的精度和可靠性，从而保障测量结果的准确性。该标准对于提高产品质量、规范市场秩序具有重要意义。
AI Summary AI generated
This standard JB/T 54254-1999 specifies product quality grading requirements for external micrometers with a graduation value of 0.01 mm and a measuring range of 0~1000 mm. It classifies products into three grades: qualified, first-class, and premium. Each grade has different requirements for indicators such as indication error, parallelism tolerance, hardness, surface roughness, measuring force, cleanliness, and life tests. Qualified products must meet the basic requirements of GB/T 1216, while first-class and premium products have stricter criteria, e.g., premium products require a screw pitch error no greater than 0.002 mm, cleanliness no greater than 7 mg, and a 100% pass rate in life tests. The standard also defines three categories of nonconformities (A, B, C) for quality evaluation in batch production and periodic inspection.
本标准JB/T 54254-1999规定了外径千分尺的产品质量分等要求，适用于分度值0.01 mm、测量范围0~1000 mm的千分尺。标准将产品分为合格品、一等品和优等品三个等级，分别对示值误差、平行度公差、硬度、表面粗糙度、测力、清洁度、寿命试验等指标提出不同要求。合格品需满足GB/T 1216基本要求，一等品和优等品则更严格，如优等品测微螺杆螺距误差不大于0.002 mm，清洁度不大于7 mg，寿命试验合格率100%。标准还规定了A、B、C三类不合格项的判定标准，用于批量生产和周期检查的质量评定。
Key Sentences extracted from text
本标准规定了分度值为0.01 mm，测微螺杆螺距为0.5mm，量程为25 mm，测量范围最大为0~1000 mm 外径千分尺（以下简称千分尺）的合格品、一等品和优等品的各项质量指标。
千分尺的示值误差和两测量面的平行度公差应不大于表1 的规定。
千分尺测微螺杆的移动应平稳，无卡滞现象，其轴向和径向间隙应不大于0.01 mm。
千分尺测量面应镶硬质合金，其硬度应不低于766 HV（≈62 HRC）；对不锈钢制造的测微螺杆和测砧，其硬度应不低于530 HV（≈51 HRC）。
千分尺的试验对象、条件、要求及试验合格率见表7 的规定。
This standard specifies the quality indicators for qualified products, first-class products, and premium products of external micrometers (hereinafter referred to as micrometers) with a graduation value of 0.01 mm, a micrometer screw pitch of 0.5 mm, a range of 25 mm, and a maximum measuring range of 0~1000 mm.
The indication error and parallelism tolerance of the two measuring faces of the micrometer shall not exceed the provisions of Table 1.
The movement of the micrometer screw shall be smooth without sticking, and its axial and radial clearances shall not exceed 0.01 mm.
The measuring faces of the micrometer shall be tipped with cemented carbide, and its hardness shall not be less than 766 HV (≈62 HRC); for the micrometer screw and anvil made of stainless steel, their hardness shall not be less than 530 HV (≈51 HRC).
The test object, conditions, requirements, and pass rate of the micrometer are specified in Table 7.
Standard Timeline
Changes from replaced version:
- 本标准与JB/T 54254—94 的技术内容一致，仅按有关规定重新进行了编辑。
- The technical content of this standard is consistent with JB/T 54254-94, only re-edited according to relevant regulations.