Valid

GB/T 28906-2025Hot-rolled steel wire rod for cold heading (English PDF)

冷镦钢热轧盘条

Preview PDF

This is a limited preview

Buy now to download the full PDF (24 pages)

Need quotation for your management?

Get a formal quotation for GB/T 28906-2025 in 30 minutes.

Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

March 28, 2025

Implementation date

October 1, 2025

Scope

GB/T 28906-2025 is the English-translated version of 冷镦钢热轧盘条.

GB/T 28906-2025 is the Chinese national standard covering the rod from which bolts, screws and studs are cold headed, 5 mm to 52 mm — the ML grades including the boron-bearing and the non-quenched-and-tempered ones, the sulphur and phosphorus limits, the mechanical properties and the low temperature impact, the decarburisation, the hardenability read from the Jominy end quench, the surface quality and the scale that a header will drag into the die, and the dimensions and coil weight.

It replaces GB/T 28906-2012, under the China Iron and Steel Association. In force from 1 October 2025. Issued on 28 March 2025, it has been in force since 1 October 2025, replacing GB/T 28906-2012.

Found what you need?

Document preview — GB/T 28906-2025

National Standard of the People's Republic of China

ICS: 77.140.60
Classification: H 44
Replacing: GB/T 28906-2012

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

1 Scope
2 Normative references
3 Terms and definitions
4 Classification and designation system
5 Order information
6 Manufacturing processes
7 Technical requirements
8 Test methods
9 Inspection rules
10 Packaging, marking and certification
Annex A (Informative) Comparison between designations in this document and relevant standards
Annex B (Informative) Mechanical properties of heat-treated specimens
Annex C (Informative) Special quality inspections
Bibliography

Foreword

This document specifies the classification and designation system, order information, manufacturing processes, technical requirements, test methods, inspection rules, and packaging, marking and certification for hot-rolled steel wire rods for cold heading.

This document is applicable to hot-rolled steel wire rods for cold heading (hereinafter referred to as "wire rods") with nominal diameters ranging from 5mm to 52mm, which are intended for manufacturing fasteners such as bolts, screws, and studs, as well as for steel wires for cold heading. For wire rods exceeding the specified size range, this document may still be referenced for guidance.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 222 Permissible tolerances for chemical composition of steel products

GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method

GB/T 223.9 Iron, steel and alloy - Determination of aluminium content - Chrome azurol S photometric method

GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method

GB/T 223.12 Methods for chemical analysis of iron, steel and alloy - The sodium carbonate separation - Diphenyl carbazide photometric method for the determination of chromium content

GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The N-benzoyl-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content

GB/T 223.26 Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method

GB/T 223.37 Iron, steel and alloy - Determination of nitrogen content - Indophenol blue spectrophotometric method after distillation separation

GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol S spectrophotometric method

GB/T 223.53 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrophotometric method for the determination of copper content

GB/T 223.54 Iron, steel and alloy - Determination of nickel content - Flame atomic absorption spectrometric method

GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method

GB/T 223.60 Iron, steel and alloy - Determination of silicon content - Gravimetric method

GB/T 223.63 Iron, steel and alloy - Determination of manganese content - Sodium (potassium) periodate spectrophotometric method

GB/T 223.78 Methods for chemical analysis of iron, steel and alloy - Curcumin spectrophotometric method for the determination of boron content

GB/T 223.79 Iron and steel - Determination of multi-element contents - X-ray fluorescence spectrometry (Routine method)

GB/T 223.81 Iron, steel and alloy - Determination of total aluminum and total boron contents - Microwave digestion-inductively coupled plasma mass spectrometric method

3 Terms and definitions

No terms or definitions are listed in this document.

4.1 Classification

This document categorizes steel wire rods into four types based on their application states: non-heat-treated, surface hardened, quenched and tempered (including boron-containing steels), and non-quenched and tempered types.

4.2 Designation system

4.2.1 Non-heat-treated, surface hardened, and quenched and tempered types (including boron-containing steels)

The grade designations for these steel types consist of three parts: The initials "ML" of the Chinese pinyin for "Mao Luo" meaning "fastener/cold heading steel", the average carbon content, and the principal alloying elements.

ML——the initials of the Chinese pinyin for "Mao Luo";

20——the average carbon content (expressed in ten-thousandths);

MnTiB——the principal alloying elements.

4.2.2 Non-quenched and tempered type

The grade designations for non-quenched and tempered steels consist of four parts: The initial "M" of the Chinese pinyin for "Mao" meaning "fastener", the initials "FT" of the Chinese pinyin for "Fei Tiao" meaning "non-quenched and tempered", the fastener strength grade, and the Chinese pinyin representing the dominant microstructure. Among them, the Chinese Pinyin letters representing the dominant microstructure are as follows: Ferrite-pearlite (base type) without additional letters; ferrite-bainite type with letter "B"; granular bainite type with letters "LB"; ferrite-martensite duplex steel with letters "DP".

M——the initial of the Chinese pinyin for "Mao";

FT——the initials of the Chinese pinyin for "Fei Tiao";

8——the strength grade number of the fastener;

B——the dominant microstructure of ferrite-bainite.

Contents of GB/T 28906-2025 Contents

10 Packaging, marking and certification

Annex A (Informative) Comparison between designations in this document and relevant standards

Annex B (Informative) Mechanical properties of heat-treated specimens

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 24 pages — is available in the English PDF.

Referenced standards

Normative references

GB/T 223.53

Cited by

LY/T 3219-2020Self-tapping screws for timber structures

Editions of GB/T 28906

Edition	Title	Revision	Status
GB/T 28906-2025	Hot-rolled steel wire rod for cold heading	current edition	Current
GB/T 28906-2012	Hot rolled wire rod for cold heading	previous edition	In force

This page sells the current edition, GB/T 28906-2025. Earlier editions are listed for reference only.

How to Download GB/T 28906-2025

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.