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This standard is equivalent to international standard ISO 7048:1998 (revision in February 1, 1999) Cross recessed cheese head screws.
This standard is a part of the series standards of "screw-in fastener" products, which consist of:
a) Slotted pan head screws: GB/T 65, GB/T 67, GB/T 68, GB/T 69, GB/T 71, GB/T 72, GB/T 73, GB/T 74, GB/T 75, GB/T 828, GB/T 829, GB/T 830, GB/T 831, GB/T 832, GB/T 833, GB/T 837, GB/T 946, GB/T 947, GB/T 948 and GB/T 949;
b) Cross recessed screws: GB/T 818, GB/T 819.1, GB/T 819.2, GB/T 820, GB/T 822, GB/T 823 and GB/T 13806.1;
c) Hexagon socket screws: GB/T 70.1, GB/T 70.2, GB/T 70.3, GB/T 77, GB/T 78, GB/T 79, GB/T 80 and GB/T 5281;
d) Hexalobular socket screws: GB/T 2672, GB/T 2673, GB/T 2674, GB/T 6190 and GB/T 6191;
e) Round nuts: GB/T 815 and GB/T 817;
f) Wood screws, head tapping screws and assemblies: GB/T 99, GB/T 100, GB/T 101, GB/T 950, GB/T 951, GB/T 952, GB/T 845, GB/T 846, GB/T 847, GB/T 5282, GB/T 5283, GB/T 5284, GB/T 6560, GB/T 6561, GB/T 6562, GB/T 6564, GB/T 13806.2, GB/T 14210, GB/T 15856.1, GB/T 15856.2, GB/T 15856.3, GB/T 9074.1, GB/T 9074.2, GB/T 9074.3, GB/T 9074.4, GB/T 9074.5, GB/T 9074.6, GB/T 9074.7, GB/T 9074.8, GB/T 9074.9 and GB/T 9074.10.
Packing technology requirements, which are not specified in ISO 7048, are specified in this standard (Table 2).
The specific property class for nonferrous metal screw, which is not provided in ISO 7048, is provided in this standard (Table 2).
Simplified designation is not specified in ISO 7048, while this standard provides a simplified example of designation (5.2) in accordance with the simplification principle of GB/T 1237.
This standard does not adopt Annex A of ISO 7048, but the contents are listed in “Normative references (Clause 2)”.
This standard is the revision of GB/T 822-1988, the main changes in this standard are as follows:
a) type Z cross recess is added;
b) specifications of thread M2 and M10 are cancelled (Table 1);
c) specifications of thread M3.5 are added (Table 1);
d) approximate mass per 1000 pieces is added(Table 1);
e) general requirements in GB/T 16938 are added (Table 2);
f) non-ferrous metal screws are added, and their property class is selected according to GB/T 3098.10 (Table 2).
This standard replaces GB/T 822-1988 from the implementation date hereof.
This standard was proposed by the State Bureau of Machine Building Industry.
This standard is under the jurisdiction of National Technical Committee on Fasteners of Standardization Administration of China.
China Academy of Machinery Science and Technology is responsible for this standard, and Beijing Standard Parts Industry Group Corporation and Shenyang Standard Parts Manufacturing Factory participated in the drafting.
The Secretariat of the National Technical Committee on Fasteners of Standardization Administration of China is in charge of the explanation of this standard.
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% approval by the member bodies voting.
International Standard ISO 7048 was prepared by Technical Committee ISO/TC 2, Fasteners.
Annex A of this International Standard is for information only.
Cheese head screws with cross recess
1 Scope
This standard specifies cross recessed cheese head screws of product grade A, property classes 4.8, 5.8, A2-70, CU2, CU3 and AL4, with threads from M2.5 to M8 inclusive and with cross recesses type H and Z.
Note: the head size of such screws is the same as GB/T 65 screws.
If specifications other than those listed in this standard are required, they shall be selected from existing standards, for example GB/T 196, GB/T 3106, GB/T 3098.1, GB/T 3098.6 and GB/T 3098.10.
2 Normative references
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. At the time of publication, all editions listed 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 65-2000 Slotted cheese head screws (eqv ISO 1207:1992)
GB/T 90-1985 Acceptance inspection, marking and packaging of fasteners (eqv ISO 3269:1984)
GB/T 196-1981 General purpose screw threads-Basic dimensions for diameter from 1 to 600mm
GB/T 197-1981 General purpose screw threads - Tolerances and fits for diameter from 1 to 355mm
GB/T 944.1-1985 Cross recesses for screws (eqv ISO 4757:1983)
GB/T 1237-2000 Designation system for fasteners (eqv ISO 8991:1986)
GB/T 3098.1-2000 Mechanical properties of fasteners - Bolts, screws and studs (idt ISO 898-1: 1999)
GB/T 3098.6-2000 Mechanical properties of corrosion-resistant stainless-steel fasteners - Part 1: Bolts, screws and studs (idt ISO 3506-1:1997)
GB/T 3098.10-1993 Mechanical properties of fasteners - Bolts, screws, studs and nuts made of non-ferrous metals (eqv ISO 8839:1986)
GB/T 3103.1-1982 (confirmed in 1988) Tolerances for fasteners - Bolts, screws and nuts (eqv ISO 4759-1:1978)
GB/T 3106-1982 (confirmed in 1988) Bolts, screws and studs; Nominal lengths and thread lengths for general purpose bolts (eqv ISO 888:1976)
GB/T 5267-2012 Electroplated coatings on threaded fasteners
GB/T 5276-1985 Fasteners; Bolts, screws, studs and nuts; Symbols and designations of dimensions (eqv ISO 225:1983)
GB/T 5779.1-2000 Fasteners - Surface discontinuities - Bolts, screws and studs for general requirements (idt ISO 6157:1988)
GB/T 16938-1997 Fasteners - General requirements for blots, screws, studs and nuts (idt SO 8992:1986)
3 Dimensions
Note: designations and symbols of dimensions shall meet GB/T 5276.
The shank diameter is approximately equal to the pitch diameter or equal to the permissible major thread diameter.
Figure 1
Table 1 Dimensions in millimeters
4 Technical conditions and normative references
Foreword I
ISO Foreword III
1 Scope
2 Normative references
3 Dimensions
4 Technical conditions and normative references
5 Designation
