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Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 10425-2025: Sintered metal friction materials - Determination of apparent hardness Status: Valid GB/T 10425: Historical versions
Basic dataStandard ID: GB/T 10425-2025 (GB/T10425-2025)Description (Translated English): Sintered metal friction materials - Determination of apparent hardness Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: H72 Classification of International Standard: 77.160 Word Count Estimation: 18,171 Date of Issue: 2025-08-01 Date of Implementation: 2026-02-01 Older Standard (superseded by this standard): GB/T 10425-2002 Issuing agency(ies): State Administration for Market Regulation, Standardization Administration of China GB/T 10425-2025: Sintered metal friction materials - Determination of apparent hardness---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT10425-2025ICS 77.160 CCSH72 National Standard of the People's Republic of China Replaces GB/T 10425-2002 Determination of apparent hardness of sintered metal friction materials Released on August 1, 2025 Implementation on February 1, 2026 State Administration for Market Regulation The National Standardization Administration issued Table of ContentsPreface III Introduction IV 1 Scope 1 2 Normative references 1 3 Terms and Definitions 1 4 Symbols and instructions 1 5 Principle 3 6 Instruments and Equipment 5 7 Sample 6 8 Test Step 6 9 Experimental data processing 8 10 Precision and Bias 8 11 Test Report 8 Appendix A (Informative) Summary of Laboratory Study Results 10 Preface 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 10425-2002 "Sintered metal friction materials - Determination of apparent hardness" and is consistent with GB/T 10425-2002. In addition to structural adjustments and editorial changes, the main technical changes are as follows. a) Added the method for determining apparent Rockwell hardness and changed the scope of application (see Chapter 1, Chapter 1 of the.2002 edition); b) Added “Symbols and Instructions” (see Chapter 4); c) Added "Principles" (see Chapter 5); d) Changed "test equipment" to "instrument equipment" and added the hardness tester used for apparent Brinell hardness and apparent Rockwell hardness test and corresponding requirements for the pressure head (see Chapter 6, Chapter 3 of the.2002 edition); e) Changed “Test specimen preparation” to “Sample” and deleted “For sintered metal friction plates with core plates, the friction layer thickness should be no less than the pressure 5 times the scar depth”, adding specific requirements for sample preparation (see Chapter 7, 4.2 of the.2002 edition); f) Changed "test method" to "test procedure", changed Table 1 and the test method content, and added the apparent Rockwell hardness test procedure Content (see Chapter 8, Chapter 5 of the.2002 edition); g) "Test results" has been deleted (see Chapter 6 of the.2002 edition); h) Added "Test Data Processing" (see Chapter 9); i) Added “Precision and Bias” (see Chapter 10); j) “Test report” has been changed (see Chapter 11, Chapter 7 of the.2002 edition). 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 is proposed and coordinated by the China Machinery Industry Federation. This document was drafted by. Huangshi Saifu Friction Material Co., Ltd., Hangzhou Advance Gearbox Group Co., Ltd., Beijing Youcai Bermuda Aviation Equipment Co., Ltd., Shaanxi Yichuang Titanium Zirconium Testing Co., Ltd., and Northwest Research Institute of Nonferrous Metals. The main drafters of this document are. Lü Bo, Xu Yao, Wang Xiufei, Xu Kun, Xu Chengfa, Zhang Lei, Li Aijun, and Tan Ping. The previous versions of this document and the documents it replaces are as follows. --- First issued as GB/T 10425-1989 in 1989, first revised in.2002; ---This is the second revision.introductionSintered metal friction materials generally have a porous structure. Therefore, they can be understood as porous composite materials. It contains both solid phase and some pores, so the test measures the apparent hardness of the material. GB/T 10425-2002 only recommends a Brinell hardness test method for the apparent hardness of sintered metal friction materials. With the continuous development of technology, new materials, new processes and new technologies have also put forward new requirements for the evaluation of the hardness of sintered metal friction materials. Japan and other countries use the Rockwell hardness test method to test the apparent hardness of sintered metal friction materials. The Brinell hardness test method uses the indentation diameter d to characterize the hardness value of the material. Its advantages are strong applicability, stable test data, and measurement accuracy. The disadvantages are that the test operation time is long, the indentation measurement is also time-consuming, and the inspection of finished products and thin parts testing are more difficult. The difference between the Rockwell hardness test method and the indentation test method is that the depth of the indentation is measured instead of the diameter of the indentation. The depth value h is used to characterize the material. The hardness index of the material is simple, quick and efficient to operate; because the test force used is small, the indentation produced is smaller than that of the Brinell hardness test. The indentation is small, so there is no obvious damage to the surface of the product. The industry standard of metal friction materials is in line with international standards. At the same time, the revision of this document also provides a platform for domestic and international companies to conduct technical exchanges and cooperation. It provides a common foundation and language for cooperation and can promote the international development of the industry. This document specifies that a carbide spherical indenter should be used to determine the Brinell hardness. The Brinell hardness symbol is HBW to avoid confusion with the old symbol. HB is confused with the symbol HBS used when using a steel ball indenter; the apparent Rockwell hardness spherical indenter is specified to be a cemented carbide spherical indenter. The head, because the tendency of the steel ball to become flat as it is used will lead to increased errors in the measurement of hardness values. Determination of apparent hardness of sintered metal friction materials1 ScopeThis document specifies the apparent Brinell hardness and apparent Rockwell hardness of sintered metal friction materials (Rockwell hardness and scale L, M, R). Method for determining superficial Rockwell hardness (with scales of 15X and 15Y). This document is applicable to the determination of the apparent hardness of sintered metal friction materials with a thickness of not less than 0.5 mm.2 Normative referencesThe contents of the following documents constitute the 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 230.1 Rockwell hardness test for metallic materials - Part 1.Test method GB/T 230.2 Rockwell hardness test for metallic materials - Part 2.Verification and calibration of hardness testers and indenters GB/T 231.1 Metallic materials Brinell hardness test Part 1.Test method GB/T 231.2 Brinell hardness test for metallic materials - Part 2.Verification and calibration of hardness testers GB/T 231.4 Metallic materials Brinell hardness test Part 4.Hardness value table GB/T 8170 Rules for rounding off values and expression and determination of limit values JJG112 Metal Rockwell Hardness Tester (A, B, C, D, E, F, G, H, K, N, T scale) JJG150 Metal Brinell Hardness Tester JJG884 Plastic Rockwell Hardness Tester3 Terms and DefinitionsThere are no terms or definitions that require definition in this document. 4 Symbols and Descriptions 4.1 Symbols, abbreviations and explanations 4.1.1 The symbols, abbreviations and corresponding explanations of the Brinell hardness test are shown in Table 1. Table 1 Brinell hardness symbols, abbreviations and descriptions Symbol/Abbreviation Term Description Unit D ball diameter mm F Test force N d Average indentation diameter, d= d1 d2 mm ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 10425-2025_English be delivered?Answer: Upon your order, we will start to translate GB/T 10425-2025_English as soon as possible, and keep you informed of the progress. The lead time is typically 2 ~ 4 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 10425-2025_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 10425-2025_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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