GB/T 5779.1

📋 Scope / 适用范围 ai_extracted

1 Scope The limits specified in this standard apply to various surface defects of bolts, screws, and studs intended for general requirements. Applicable bolts, screws, and studs: - Nominal thread diameter equal to or greater than 5 mm; - Product grades A and B; - Property classes equal to or less than 10.9, unless otherwise specified in the product standard or by special agreement between the supplier and the purchaser. 1.2 Limits for surface defects of bolts, screws, and studs with special requirements (e.g., automated assembly) are specified in GB/T 5779.3. When the engineering technical conditions require stricter control of surface defects in bolts, screws, and studs, the applicable limits shall be specified in the relevant product standard or stipulated by the purchaser in the inquiry and order. 1.3 Even if surface defects reach the allowable limits specified in Chapter 3, the mechanical and performance characteristics of the product shall still comply with the minimum requirements of GB/T 3098.1. Additionally, the dimensional requirements of the corresponding product standard shall be met. Note:

📝 Foreword / 前言 ai_extracted

This standard is identical to the international standard ISO 6157-1:1988 (Fasteners — Surface discontinuities — Part 1: Bolts, screws and studs for general requirements). This standard is a revision of GB/T 5779.1-1986, with the following main modifications: a) Adjustment of the permissible limits for "forging cracks" (Clause 3.1.3); b) Comprehensive specification of the inspection and judgment procedures for surface discontinuities, as well as the sampling plan (Chapter 4 and Appendix A). This standard replaces GB/T 5779.1-1986 from the date of implementation. Appendix A of this standard is a normative appendix. This standard was proposed by the State Bureau of Machinery Industry. This standard is under the jurisdiction of the National Technical Committee on Fasteners Standardization. This standard was drafted by the Machinery Science Research Institute. This standard is interpreted by the Secretariat of the National Technical Committee on Fasteners Standardization. 369 www.bzfxw.com GB/T 5779.1-2000 ISO Foreword ISO (International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO 6157-1 was prepared by ISO/TC 2, Fasteners. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. www.bzfxw.com National Standard of the People's Republic of China Fasteners — Surface discontinuities — Bolts, screws and studs for general requirements GB/T 5779.1-2000 idt ISO 6157-1:1988 Replaces GB/T 5779.1-1986

📚 References & Relations / 引用与关联

🔗 Related Standards / 同类标准