In-Depth Analysis and Trend Insights of the Four Major Automotive Manufacturing Processes in 2025

In today’s highly competitive automotive market, the advancement and stability of manufacturing processes are key manifestations of an enterprise’s core competitiveness. In 2025, driven by continuous technological progress and increasingly diversified consumer demands, the four major automotive manufacturing processes—stamping, body welding, painting, and final assembly—are undergoing unprecedented transformation and upgrading. This article provides an in-depth analysis of the current status, technical highlights, and development trends of these four processes, and explains how they collectively shape the future of automotive manufacturing.

Refinement and Intelligent Development of the Stamping Process

As the first step in automotive manufacturing, the stamping process directly determines the smooth progress of subsequent processes and the overall quality of the vehicle. In 2025, stamping is characterized by significant refinement and intelligence.

From the perspective of refinement, the selection of stamping materials has become more sophisticated. Low-carbon steel is generally used, and most body frame components and exterior panels are stamped from steel sheets. Special automotive steel sheets feature excellent deep-drawing performance and are less prone to cracking. Different body parts use different materials based on functional requirements. For example, zinc-coated steel sheets are used for corrosion-prone parts such as fenders and roof panels, while high-strength steel sheets are used for high-stress components like radiator support cross members and upper side beams. In passenger car body structures, commonly used steel sheet thickness ranges from 0.6 to 3 mm: outer panels typically use 0.6–0.8 mm sheets, inner panels 1.0–1.8 mm, and reinforcement panels 2.0–2.5 mm. This refined material selection ensures optimal performance and quality for each body component.

In terms of intelligence, the upgrading of stamping equipment is crucial. At present, large stamping lines produced in China for manufacturing large passenger car exterior panels have reached internationally advanced levels. High-performance single-press linkage production lines feature large tonnage, long stroke, large bed size, high-capacity cushions, robotic automatic loading and unloading systems, fully automatic die-changing systems, and comprehensive touchscreen monitoring systems. These intelligent systems offer high production speed and precision, significantly improving efficiency while reducing labor costs and operational risks, thus enabling automated and intelligent stamping production.

Diversification and Efficiency Enhancement of the Body Welding Process

The body welding process plays a vital role in vehicle body manufacturing by joining stamped body panels through heating or pressure to form the body assembly. In 2025, this process demonstrates clear trends toward diversification and higher efficiency.

Diversification is reflected in the variety of welding methods used. Resistance spot welding, the most commonly applied method, is suitable for thin steel sheets. During operation, two electrodes press the sheets together while electric current generates heat at the contact point, forming a strong joint. A typical passenger car body requires several thousand weld spots, each capable of withstanding a tensile force of about 5 kN. In addition to spot welding, CO₂ shielded welding, projection welding, and stud welding are widely used in different areas. CO₂ welding is mainly applied to body compartments, rear axles, and frames; projection welding is commonly used for welding nuts and bolts onto body components; and stud welding is used for end-face stud attachment. The combined application of these methods ensures body structural strength and welding quality.

Efficiency improvements are largely driven by the use of automotive industrial cranes, as well as continuous optimization of welding equipment and fixtures. Various types of spot welding machines and welding guns are available, including X-type welding guns, suspended spot welders, stationary spot welders, C-type welding guns, integrated spot welders, automatic welding guns, and robotic spot welding systems, all of which meet different welding scenarios and precision requirements. Welding fixtures also play a critical role by ensuring correct assembly positioning, stabilizing workpieces during welding, facilitating operation, improving efficiency, and guaranteeing accurate geometry and dimensions after welding. The use of large-scale welding line fixtures further enhances large-volume and high-efficiency body welding production.

Environmental Protection and Quality Upgrading of the Painting Process

The painting process serves two essential functions in automotive manufacturing: corrosion protection and aesthetic enhancement. In 2025, significant progress has been made in both environmental protection and quality improvement.

Environmental protection has become an inevitable trend. As environmental regulations grow increasingly stringent, automotive manufacturers are actively adopting more eco-friendly coating materials and processes. The use of water-based coatings and high-solid-content coatings has increased steadily. These materials emit far fewer volatile organic compounds (VOCs) than traditional solvent-based paints, significantly reducing environmental impact. At the same time, exhaust gas treatment technologies in painting processes have been continuously upgraded. Advanced purification systems, such as activated carbon adsorption and catalytic combustion, are widely applied to further reduce harmful emissions, enabling greener painting production.

Quality enhancement is reflected in the refinement and premiumization of painting processes. Pretreatment processes are more rigorous, ensuring surfaces are free of impurities and oil, and forming a complete phosphating layer that enhances adhesion between the electrophoretic coating and the metal surface, improves corrosion resistance, and provides a certain level of electrical insulation. The cathodic electrophoretic coating process has been continuously optimized, with coating layers playing a more prominent role in improving corrosion resistance, enhancing mid-coat adhesion, and protecting internal cavities and seams. Processes such as PVC application, intermediate coating, and top coating are all controlled with more precise parameters to ensure stable and improved coating quality. High-end painting equipment further supports quality enhancement. The application of robotic spraying systems and ostrich-feather dust-removal devices improves coating uniformity and appearance, significantly enhancing vehicle exterior quality.

Integration and Intelligent Transformation of the Final Assembly Process

Final assembly is the last stage of automotive manufacturing, where the body, engine, transmission, instrument panel, lighting systems, doors, and other components are assembled into a complete vehicle. In 2025, final assembly is undergoing profound integration and intelligent transformation.

Integration is reflected in the systematization and modularization of final assembly lines. Mechanical final assembly line systems include vehicle assembly lines, body conveying lines, buffer storage lines, and lifts, forming an integrated whole. Final assembly workshops typically include front-end module assembly, instrument panel assembly modules, lighting assembly modules, and chassis assembly modules. After module assembly and component installation, vehicles undergo inspections and adjustments such as wheel alignment and headlamp aiming before rolling off the line. This integrated production model improves efficiency, shortens production cycles, and facilitates quality control and management.

Intelligence has become a new driving force in final assembly development. The intelligence level of major assembly equipment continues to rise. Conveying systems, major assembly loading equipment, various fluid filling systems, end-of-line inspection equipment, and specialized assembly devices have all achieved automated and intelligent control. For example, engine and axle assembly loading equipment uses advanced conveying and lifting technologies to ensure precise positioning and rapid installation. Fluid filling systems automatically identify vehicle models and required quantities, enabling precise filling. Intelligent end-of-line inspection systems conduct comprehensive, rapid, and accurate testing of vehicle performance indicators to ensure every vehicle meets quality standards. Assembly tools are also becoming more intelligent: pneumatic tools, manual tools, and torque wrenches are equipped with sensors and control systems that monitor operating status and torque output in real time, ensuring consistent assembly quality.

Conclusion

In 2025, the four major automotive manufacturing processes—stamping, body welding, painting, and final assembly—are rapidly evolving toward refinement, intelligence, diversification, efficiency, environmental sustainability, quality enhancement, integration, and intelligent operation. Refined and intelligent stamping ensures high-quality body component production; diversified and efficient welding guarantees strong and reliable body assemblies; environmentally friendly and high-quality painting improves durability and aesthetics; and integrated and intelligent final assembly enables efficient and precise vehicle production. Continuous progress and innovation across these processes not only enhance manufacturing efficiency and product quality but also promote the sustainable development of the automotive industry, delivering higher-quality, more environmentally friendly, and safer vehicles to consumers. Looking ahead, as technology continues to advance and market demands evolve, automotive manufacturing processes will keep transforming, bringing both new opportunities and challenges to the industry.