GB/T 1231-2024High strength bolts with large hexagon head assemblies for steel structures (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document replaces GB/T 1231-2006 "Technical requirements for high-strength large hexagon head bolts, large hexagon nuts and washers for steel structures".

GB/T 1228-2006 "High-strength large hexagon head bolts for steel structures", GB/T 1229-2006 "High-strength large hexagon nuts for steel structures"

and GB/T 1230-2006 "High Strength Washers for Steel Structures". This document is based on GB/T 1231-2006 and integrates GB/T 1228-

2006, GB/T 1229-2006, GB/T 1230-2006.Compared with GB/T 1231-2006 and other documents, in addition to structural adjustments and

In addition to editorial changes, the main technical changes are as follows.

a) Added bolt connection type diagram (see Chapter 4);

b) Added the specifications of M33 and M36 for large hexagon head bolts, large hexagon nuts and washers in bolted connection pairs (see Chapter 5);

c) The theoretical mass of large hexagon head bolts, large hexagon nuts and washers in bolted joints has been changed (see Chapter 5, GB/T 1228-

2006~Chapter 3 of GB/T 1230-2006);

d) Added gasket type (see 5.3);

e) Added materials used (see 6.1);

f) The requirements for tensile strength, cross-sectional shrinkage and absorbed energy in the mechanical properties of bolt specimens have been changed (see 6.2.1.1, GB/T 1231- 2006, 3.2.1.1);

g) Changed the upper limit of tensile load and core hardness of 10.9S bolt wedge load test (see 6.2.1.2, GB/T 1231-2006 3.2.1.2);

h) Added the provisions for the carburized layer of bolts (see 6.2.1.3);

i) The hardness requirements for 10H nuts have been changed (see 6.2.2.2, 3.2.2.2 of GB/T 1231-2006);

j) The standard deviation of the torque coefficient is changed to the requirement for the coefficient of variation (see 6.3.1, 3.3.1 of GB/T 1231-2006);

k) Added processing requirements for nut threads (see 6.4.3);

1 Scope

This document specifies the types, dimensions, and technical requirements of high-strength large hexagonal bolt connections (hereinafter referred to as "bolt connections") for steel structures.

Requirements, test methods, inspection rules and marking, logo, label, packaging and quality inspection report.

This document is applicable to railway and highway bridges, tower mast structures, boiler steel structures, industrial and civil buildings, lifting machinery and other steel structures.

Wiping type high strength bolt connection pair.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

GB/T 2 Fastener external thread parts end

GB/T 90.1 Fastener acceptance inspection

GB/T 196 Basic dimensions of common threads

GB/T 197 General thread tolerances

GB/T 228.1 Tensile test of metallic materials Part 1: Room temperature test method

GB/T 229 Charpy pendulum impact test method for metallic materials

GB/T 230.1 Rockwell hardness test for metallic materials Part 1: Test method

GB/T 699 High-quality carbon structural steel

GB/T 1237 Fastener marking method

GB/T 3077 Alloy structural steel

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

GB/T 3098.2 Mechanical properties of fasteners - Nuts

GB/T 3103.1 Fastener tolerances Bolts, screws, studs and nuts

GB/T 3103.3 Fastener tolerances Flat washers

GB/T 4340.1 Vickers hardness test for metallic materials Part 1: Test method

GB/T 5276 Fasteners Bolts, Screws, Studs and Nuts Size Codes and Markings