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GB/T 45779-2025Welded shaped steel tubes for structure (English PDF)

结构用焊接异型钢管

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Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

June 30, 2025

Implementation date

January 1, 2026

Scope

GB/T 45779-2025 is the English-translated version of 结构用焊接异型钢管.

GB/T 45779-2025 is the Chinese national standard covering welded steel tube in sections other than round — the classification and code, what an order has to state, the manufacturing route, the chemical composition and mechanical properties, the dimensions and tolerances, the flattening test, the zinc coating weight and its uniformity where the tube is galvanised, and the section properties tabulated for each shape, which is what a designer actually works from. Appendix A alone runs to thirty-six pages of section shapes, sizes and section properties. First edition, under the China Iron and Steel Association. In force from 1 January 2026. Issued on 30 June 2025, it has been in force since 1 January 2026.

Document preview — GB/T 45779-2025

National Standard of the People's Republic of China

ICS: 77.140.75
Classification: H 48

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

PrefaceIII
1 Scope1
2 Normative references1
3 Terms and Definitions2
4 Classification and Code2
5 Order Content3
6 Manufacturing Process3
7 Technical Requirements5
8 Test methods21
9 Inspection Rules22
10 Marking, packaging, storage and quality certificate23
Appendix A (Normative) Cross-sectional shape, size specifications and cross-sectional properties of steel pipes24
Appendix B (Normative) Steel Pipe Flattening Test Method60
Appendix C (Normative) Determination of Weight of Zinc Coating - Antimony Chloride Method62
Appendix D (Normative) Uniformity Test of Galvanized Coating - Copper Sulfate Immersion Method64
Appendix E (Informative) Calculation of Sectional Properties Formula65

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.

Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents.

This document was proposed by the China Iron and Steel Association.

This document is under the jurisdiction of the National Technical Committee on Steel Standardization (SAC/TC183).

This document was drafted by: Zhejiang Dewei Stainless Steel Pipe Co., Ltd., Tianjin Youfa Dezhong Steel Pipe Co., Ltd., Zhejiang Jinzhou Pipe Dao Technology Co., Ltd., Handan Zhengda Pipe Group Co., Ltd., Fujian Qingtuo Special Steel Technology Research Co., Ltd., Guangdong Zhenxiong Steel Pipe Co., Ltd., Tianjin Yuantai Derun Steel Pipe Manufacturing Group Co., Ltd., and Metallurgical Industry Information Standards Research Institute.

The main drafters of this document are: Xie Yi, Ding Xiuchen, Yang Weifang, Zhang Hongshun, Jiang Laizhu, Wang Fang, Huang Yalian, Li Qi, Mo Peiming, Zhao Fuliang, Zhong Xuequan, Wang Yuanzhi, Ren Yong, Chen Yao, Shen Chenxia, Chen Zisen, Guo Yong, and Xue Jianzhong.

Welded special-shaped steel pipes for structures

1 Scope

This document specifies the classification and code, ordering content, manufacturing process, technical requirements, test methods, inspection Regulations, marking, packaging, storage and quality certificates.

This document is applicable to welded special-shaped steel pipes (with (hereinafter referred to as "steel pipe").

2 Normative references

GB/T 222

GB/T 223.9

GB/T 223.11

GB/T 223.12

GB/T 223.14

GB/T 223.18

GB/T 223.19

GB/T 223.23

GB/T 223.25

GB/T 223.26

GB/T 223.28

GB/T 223.36

GB/T 223.37

GB/T 223.40

GB/T 223.53

GB/T 223.58

GB/T 223.59

GB/T 223.60

GB/T 223.62

GB/T 223.63

GB/T 223.64

GB/T 223.72

GB/T 223.81

GB/T 223.84

GB/T 223.85

GB/T 223.86

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 55 pages — is available in the English PDF.

Referenced standards

Normative references

GB/T 223.9 · GB/T 223.11 · GB/T 223.12 · GB/T 223.14 · GB/T 223.19 · GB/T 223.28 · GB/T 223.37 · GB/T 223.53 · GB/T 223.58 · GB/T 223.60 · GB/T 223.63 · GB/T 223.64 · GB/T 223.84 · GB/T 223.85 · GB/T 223.86

Editions of GB/T 45779

Edition	Title	Revision	Status
GB/T 45779-2025	Welded shaped steel tubes for structure	current edition	Current

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