GB/T 794-2021Strenthened cup head square neck bolts (English PDF)

Foreword

This document was drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

This document is one of the series national standards of "Square Neck Bolts", of which the following documents has been issued.

-- GB/T 10, Countersunk head square neck bolts;

-- GB/T 12, Cup head square neck bolts;

-- GB/T 14, Mushroom head square neck bolts;

-- GB/T 794, Strengthened cup head square neck bolts;

-- GB/T 801, Cup head square neck bolts with small head and short neck - Product grade B.

This document replaces GB/T 794-1993 Strengthened cap head square neck bolts; compared with GB/T 794-1993, in addition to editorial changes, the main technical changes of this document are as follows.

a) Replace "commodity specification range" with "optical length range" (see Table 1, Table 2; Table 1 and Table 2 of the 1993 edition);

b) Unify the referenced thread standards as GB/T 193, GB/T 9145, GB/T 9146 (see Table 3; Table 3 of the 1993 edition);

c) Add the general technical conditions, which shall be in accordance with GB/T 16938 (see Table 3);

d) Delete grade 3.6 from, and add grade 4.6 to, type B products (see Table 3; Table 3 of the 1993 edition);

e) Delete the oxidized surface treatment (see Table 3 of the 1993 edition);

f) Add the technical requirements for electroplating of steel bolts, which shall be in accordance with GB/T 5267.1 (see Table 3);

g) Add the technical requirements for non-electrolytically applied zinc flake coatings, which shall be in accordance with GB/T 5267.2 (see Table 3);

h) Add the technical requirements for hot-dip galvanizing of steel bolts, which shall be in accordance with GB/T 5267.3 (see Table 3);

1 Scope

This document specifies the type, size, technical conditions and marking of strengthened cup head square neck bolts.

This document is applicable to strengthened cup head square neck bolts with thread specifications of M6 ~ M20 and product grades of B (type A) and C (type B).

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 2, Fasteners - Ends of parts with external thread

GB/T 90.1, Fasteners - Acceptance inspection

GB/T 90.2, Fasteners - Marking and packaging

GB/T 193, General purpose metric screw threads - General plan

GB/T 1237, Designation system for fasteners

GB/T 3098.1, Mechanical properties of fasteners - Bolts, screws and studs

GB/T 3098.6, Mechanical properties of fasteners - Stainless steel bolts, screws and studs

GB/T 3103.1, Tolerances for fasteners - Bolts, screws, studs and nuts

GB/T 5267.1, Fasteners - Electroplated coatings

GB/T 5267.2, Fasteners - Non-electrolytically applied zinc flake coatings

GB/T 5267.3, Fasteners - Hot dip galvanized coatings

GB/T 5276, Fasteners - Bolts, screws, studs and nuts - Symbols and descriptions of dimensions

GB/T 5779.1, Fasteners - Surface discontinuities - Bolts, screws and studs for general requirements […]