GB/T 800-2020Countersunk head double nib bolts (English PDF)

Foreword

This Standard is one of the "countersunk head bolts" series of national standards. This series of standards include:

---GB/T 10 Countersunk Head Square Neck Bolts;

---GB/T 11 Countersunk Head Nib Bolts;

---GB/T 800 Countersunk Head Double Nib Bolts.

This Standard was drafted in accordance with the rules in GB/T 1.1-2009.

This Standard serves as a replacement of GB/T 800-1988 Flat Countersunk Double Nib Bolts. In comparison with GB/T 800-1988, the main technical changes are as follows:

---General technical requirements are added (GB/T 16938) (see Table 2);

---The technical requirements for non-electrolytically applied zinc flake coatings (GB/T 5267.2) and hot dip galvanized coatings (GB/T 5267.3) are added (see Table 2). This Standard also makes the following editorial modification:

---The English title of the Standard is modified.

1 Scope

This Standard specifies the types and dimensions, technical conditions, reference standards and markings of countersunk head double nib bolts.

This Standard is applicable to countersunk head double nib bolts with a thread specification of M6 ~ M12, performance grade of Grade 4.8 and product grade of Grade C.

2 Normative References

The following documents are indispensable to the application of this document. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) 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 196 General Purpose Metric Screw Threads - Basic Dimensions

GB/T 197 General Purpose Metric Screw Threads - Tolerances

GB/T 1237 Designation System for Fasteners

GB/T 3098.1 Mechanical Properties of Fasteners - Bolts, Screws and Studs

GB/T 3103.1 Tolerances for Fasteners - Bolts, Screws 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 […]