GB/T 25821-2023 (English Version)

Standard No.: GB/T 25821-2023
Language: Chinese, Available in English version
Release Date: 2023
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 25821-2023
Replace: GB/T 25821-2010

Scope: This document specifies the classification and marking, ordering content, size, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of stainless steel strands (hereinafter referred to as "steel strands"). This document is applicable to stainless steel strands composed of multiple round cross-section stainless steel wires (hereinafter referred to as "steel wires") mainly used for building structures and architectural decoration. Stainless steel strands for other purposes can be used as a reference.

Introduction

1. Standard background and technical evolution analysis

GB/T 25821—2023 is the latest version of Stainless Steel Strand, replacing the old standard from 2010. This revision mainly optimizes product classification, term definitions, technical requirements and test methods to meet the demand for high-strength and corrosion-resistant materials in the fields of building structures and decoration.

2. Comparison of standard frameworks

Standard dimensions	Old version GB/T 25821—2010	New version GB/T 25821—2023
Classification and marking	Definition of stainless steel strand is not clear	New terms: stainless steel strand, nominal cross-sectional area of steel strand
Strength grade	Covering grade 120 to grade 180	Adjusted to grade 1320, grade 1420, grade 1520
Technical requirements	No detailed provisions for elastic modulus	Newly added elastic modulus not less than 1.1×10^5 N/mm²

3. Interpretation of the main contents of the standard

3.1 Classification and marking

The new standard adds the definition of nominal cross-sectional area of steel strands to facilitate unified calculation and marking. Table 1 lists in detail the nominal diameter ranges and corresponding technical parameters of different structures (such as 1×7, 1×19).

3.2 Technical requirements upgrade

Material properties: Steel wire should comply with the austenitic stainless steel specified in GB/T 4240, with grades including 06Cr19Ni10, 022Cr17Nil2Mo2, etc.
Mechanical properties: The minimum breaking force and elastic modulus are both improved to ensure the bearing capacity of the product in the building structure.

3.3 Experimental method optimization

The elastic modulus determination method specified in GB/T 24191 is added to ensure the scientificity and accuracy of the experimental data. At the same time, the breaking force test and lay length requirements are refined.

4. Implementation Suggestions

4.1 Notes for Purchasers

Specify the order content, including structure, nominal diameter and tensile strength level.
Choose products with packaging and markings that comply with GB/T 2104.

4.2 Suggestions for Manufacturers

Strictly control the diameter deviation and out-of-roundness of the steel wire in accordance with the standard requirements.
Optimize the twisting process to ensure that the twist directions of adjacent layers of steel wire are opposite and the twist length is uniform.

4.3 Suggestions for Users

Rationally select the model and strength level of steel strands in building structures.
Carry out strict inspection before construction to ensure that the product meets the design requirements.

GB/T 25821-2023 Referenced Document

GB/T 2104 Steel wire ropes.Packing,marking and certificate.General requirements
GB/T 24191 Steel wire ropes.Determination of the actual modulus of elasticity
GB/T 4240 Stainless steel wires
GB/T 8358 Method for determination of breaking force of steel wire rope
GB/T 8706 Steel wire ropes.Vocabulary,designation and classification

GB/T 25821-2023 history

2023 GB/T 25821-2023 stainless steel strand
2010 GB/T 25821-2010 Stainless steel wire strand