This standard is identical to international standard ISO 4759-3:2000 "Tolerances for Fasteners — Part 3: Plain Washers for Bolts, Screws and Nuts — Product Grades A and C".
GB/T 3103 consists of the following parts, under the general title "Tolerances for Fasteners":
— GB/T 3103.1-1982 Tolerances for Fasteners — Bolts, Screws and Nuts
— GB/T 3103.2-1982 Tolerances for Fasteners — Bolts, Screws and Nuts for Fine Mechanics
— GB/T 3103.3-2000 Tolerance for Fasteners — Plain Washers
— GB/T 3103.4-1992 Tolerance for Fasteners — Components for Bolted Connections Made Mainly from Materials with a High Temperature Strength
The Contents of ISO 4753-3 do not adopted in this standard and its text has been listed in Normative References (Chapter 2).
This standard is the revision of GB/T 3103.3-1982, main modifications are as follows:
a) The dimensional tolerance not specified in h1 of Grade C products (see 3.1);
b) Supersedes "Thickness variation Δh" with "parallelism", and this index has no requirements on Grade C products (see 3.5.1);
c) No requirements on the flatness of Grade C products (see 3.5.3);
d) Appendix A is added.
This standard supersedes GB/T 3103.3-1982 from the implementation date hereof.
Appendix A in this standard is informative.
This standard was proposed by State Bureau of Machine Building Industry.
This standard is under the jurisdiction of National Technical Committee on Fasteners of Standardization Administration of China.
This standard was drafted by the Academy of Machinery Science & Technology.
Secretariat of National Technical Committee on Fasteners of Standardization Administration of China is in charge of the explanation of this standard.
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ISO Foreword
ISO (the 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 4759-3 was prepared by Technical Committee ISO/TC 2, Fasteners.
This third edition cancels and replaces the second edition (ISO 4759-3:1991), of which has been technically revised.
ISO 4759 consists of the following parts, under the general title, Tolerances for fasteners:
— Part 1: Bolts, screws, studs and nuts — Product grades A, B and C
— Part 2: Bolts, screws and nuts with thread diameters from 1 up to 3 mm and product grade F, for fine mechanics
— Part 3: Plain washers for bolts, screws and nuts — Product grades A and C
Appendix A of this part of ISO 4759 is for information only.
NATIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
中華人民共和國國家標準
Tolerances for Fasteners — Plain Washers
緊固件公差 平墊圈
GB/T 3103.3-2000
idt ISO 4759-3:2000
Supersedes GB/T 3103.3-1982
1 Scope
This standard specifies the tolerances for punched plain washers of product grades A and C, for use with bolts, screws and nuts of nominal thread diameters of from 1 mm to 150 mm inclusive.
It is recommended that these tolerances also be used for non-standard washers.
Note: The product grade refers to the quality of the product and to the size of the tolerances.
Appendix A (informative) presents tolerances taken from GB/T 1800.2 and GB/T 1800.4.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and Parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
GB/T 1182-1996 Geometrical tolerancing — Generalities, definitions, symbols, indications on drawings (eqv ISO 1101:1983)
GB/T 1800.2-1998 Limits and fits — Bases — Part 2: Basic rules of tolerances, deviations and fits (eqv ISO 286-1:1988)
GB/T 1800.4-1999 Limits and fits — Tables of standard tolerance grades and limit deviations for holes and shafts (eqv ISO 286-2:1996)
GB/T 5267-1985 Electroplated coatings on threaded fasteners
GB/T 16671-1996 Geometrical tolerancing — Maximum material requirement, least material requirement and reciprocity requirement (eqv ISO 2692:1996)
3 Tolerances
The tolerances for plain washers of product grades A and C are given in Table 1.
Unless otherwise specified, the tolerances specified in this standard apply to washers prior to coating (GB/T 5267).
Deviations from the tolerances specified in this standard are permitted in product standards only for valid technical reasons. In cases where there is a difference between the tolerance requirements in this standard and the product standard, the latter takes precedence.
The tolerances of form and position are specified and indicated according to the definitions of GB/T 1182 and GB/T 16671.
