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Focus on Failure Mechanism and Testing Evaluation, Keep Pace with Cutting-edge Trends of International Standards

     On October 18, the 2026 Fastener and International Standard Exchange Conference was held at Ningbo Nanyuan Wanghai Hotel. Hosted by China Machinery Research Institute of Standards and Technology (Beijing) Co., Ltd. and undertaken by the Advanced Manufacturing Standard Internationalization Research Center, the conference focused on core topics including material properties, manufacturing processes, quality control, failure analysis and evolution of international standards for fasteners. Experts from German Fastener Association, McGill University in Canada, EJOT GmbH in Germany, Northwestern Polytechnical University and leading domestic fastener enterprises gathered for special discussions. Ningbo China Machinery Mechanical Parts Testing Co., Ltd. was invited to attend the conference, and conducted in-depth technical exchanges with domestic and overseas standardization experts and industry technical colleagues on testing and evaluation technologies, root cause tracing of failures, iteration of international standards and other topics.

Technical Exchange

     As a third-party professional testing institution rooted in Ningbo’s fastener industrial cluster, Ningbo China Machinery Testing has long been engaged in fastener product testing, failure analysis and standard development & verification. Attending this conference enables the company to systematically study the latest progress of international standards in the fastener sector and builds an important communication platform for aligning its testing technical capabilities with international specifications.

Focus  Focus on Failure Mechanism and Source Tracing: From Fracture Judgment to δ-Ferrite Metallographic Analysis

     The technical reports of the conference covered multiple key areas including failure mechanism research, prevention and control of manufacturing process defects, reliability of joint interfaces, and development and revision of international standards. Professor Salim Brahimi from McGill University systematically discussed internal hydrogen embrittlement and environmental hydrogen embrittlement of high-strength fasteners, defined the critical hardness of ductile-brittle transition at 39 HRC, and pointed out that intergranular fracture in fracture analysis is not equivalent to hydrogen embrittlement failure, helping avoid common misunderstandings in failure judgment.

     Dr. Stefan Beyer focused on δ-ferrite defects during quenching and tempering of Grade 10.9 and 12.9 high-strength fasteners, illustrated the formation mechanism of phosphorus diffusion caused by residual phosphating layer, and emphasized that δ-ferrite must be strictly distinguished from surface decarburization structure in failure analysis, providing cutting-edge international technical basis for improving the failure analysis technical system.

Two-way Feedback Between Industrial Practice and Testing Data

General Manager Xu Pengfei of Jinding

     Combined with the industrial production practice of high-strength bolts, Xu Pengfei, General Manager of Ningbo Jinding, sorted out key control points such as material selection, heat treatment process and strength-hardness matching, and put forward the practical demands of the industry for testing evaluation and standard verification. After the meeting, Ningbo China Machinery Testing held special exchanges with him on enabling process control via testing data. The two parties explored to reversely locate deviations in heat treatment and surface treatment processes based on evaluation results of hardness gradient, metallographic structure, fracture morphology and delayed fracture, and build a collaborative path where testing identifies process fluctuations and standard verification guarantees heat treatment quality.

New Perspectives on Friction and Wear of Joint Interfaces and Testing Evaluation Technology

Professor Xu Chao

     Professor Xu Chao from Northwestern Polytechnical University extended the research perspective from single fasteners to fretting friction and wear of bolted joint interfaces, analyzed the internal mechanism of interface wear inducing fatigue damage, stiffness degradation and preload relaxation, and introduced a self-developed high-precision test platform of his team, which can synchronously collect fretting displacement, friction force and bolt preload. Relevant test data revealed the significant influence of surface roughness on the service reliability of connections, providing important inspiration for the institute to expand component reliability evaluation services under complex working conditions. Follow-up plans include developing testing services such as preload attenuation under dynamic conditions, interface fretting wear and anti-loosening performance of systems.

Peter Daamen, Chair of ISO/TC 2

     Peter Daamen, Chair of ISO/TC 2, shared the application practice of Layered Process Audit (LPA) in fastener manufacturing, and explained its risk-oriented and multi-level process inspection philosophy. Different from traditional product audit and system audit, LPA is designed to reduce deviations between process specifications and on-site implementation, offering new ideas for testing institutions to expand services from final product testing to front-end quality early warning of manufacturing processes. The conference released updates on multiple international standards including coating assessment and hexagon socket set screws. The company followed up the relevant technical points synchronously to make technical preparations for implementing new standards and undertaking standard development and verification tasks.

Take Testing and Evaluation as the Fulcrum to Continuously Improve Regional Fastener Quality

     Relying on the technical accumulation of China Academy of Machinery Science and Technology Group and the geographical advantages of Ningbo’s fastener industry, Ningbo China Machinery Testing has established a complete technical service system covering raw material analysis, mechanical property testing, failure analysis, and standard development & verification. Attending this conference is an important practice for the company to deeply integrate into the international standardization technical network and align testing capabilities with the global cutting-edge. In the next step, the company will translate the failure analysis methodologies, coating assessment specifications and connection reliability evaluation ideas obtained at the conference into concrete actions for capacity building and testing project upgrading. It will continue to provide professional technical support for fastener enterprises in Ningbo and surrounding areas, including quality diagnosis, export compliance and standard implementation, and help improve the quality level of the regional fastener industry.