As electric vehicles (EVs) reduce engine noise, the overall NVH (Noise, Vibration, and Harshness) background has decreased significantly, amplifying previously hidden structural noises. Industry studies show that structural noises are rising sharply, with one of the main causes being micro-loosening of screws. Minor issues like “clunking sounds while driving,” “dashboard squeaks at low speeds,” or “door rattles on rough roads” are closely related to stress changes in fastened connections. Screw loosening has therefore shifted from a minor after-sales issue to a key indicator of overall vehicle quality.

Why Screws Loosen

Engineers typically identify four main causes:

Thermal expansion and contraction from temperature cycles, leading to preload loss;

Stiffness differences in assembled materials, causing micro-slippage at connection interfaces;

Self-loosening under vibration, common in chassis, suspension, and e-drive systems;

Assembly torque inconsistencies, angle deviations, and unstable lubrication.

Even minute displacements can cause relative motion under vibration, producing friction, chirping, or tapping noises. Some loosenings generate tiny wear particles, creating multi-point noise inside cavities, making source tracing difficult—often a “nightmare” for after-sales engineers.

EVs Pose New Challenges for Fastening Systems
 EVs increasingly use aluminum alloys, composites, and thin-walled components. These lightweight materials have lower stiffness and higher deformation, magnifying micro-movement and friction at connections. Critical structures like battery packs are highly sensitive, where any bolt loosening may cause vibrations, resonance, or safety concerns. High-frequency vibrations in EV powertrains further amplify fastener stress instability. Consequently, OEMs now prioritize fastener stability in new platform development and invest in torque traceability, robotic assembly compensation, and high-precision friction coefficient control technologies.

The Rising Importance of Fastener Technology
 Noise control in vehicles is no longer just an NVH responsibility; it is a system-level engineering challenge spanning materials, structural design, supply chain management, and assembly. Fasteners sit at the foundation of this chain, carrying high risk while being difficult to monitor—explaining why OEM engineers are increasingly focusing on the “Fastener Technology Zone” at industry expos. Every incremental improvement in connection technology can significantly enhance the end-user experience.

Industry Exhibitions as Platforms for Knowledge Exchange
 As quality competition becomes central in the automotive industry, fasteners have evolved from a “minor issue” to a critical factor in vehicle reliability and noise performance. Serving as a key platform for industry technology exchange, the 16th Fastener Expo Shanghai 2026 (June 24–26, 2026) will bring together OEMs, component suppliers, fastener manufacturers, and material and equipment providers to discuss critical topics including anti-loosening technologies, torque control, digital assembly, and material tribology. Engineers, procurement professionals, and supply chain managers will gain insights into the future trajectory of fastener technology.

After fifteen consecutive editions, the Fastener Expo Shanghai (FES) has developed into one of the “three major global fastener trade shows.” Its exhibitors, product quality, event content, the number of domestic and international visitors, and on-site transaction volume all set industry benchmarks. In 2025, the expo further became the largest fastener exhibition in the world in terms of exhibition area.

Official Website: www.fastenerexpo.cn/en
Media Contact: Goblic Hu
Email: goblic.hu@ebseek.com
Phone: +86 138 1631 0340