Introduction

With the rapid development of global infrastructure construction and the new energy industry, the connector and fastener industry is undergoing a new round of technological upgrades. As key components in connection systems, flexible adapter plates and hanger bolts are playing an increasingly important role in photovoltaic power stations, building seismic resistance, and mechanical and electrical pipeline support. In 2024, this field has achieved significant progress in terms of technological innovation, standard specifications, and market applications, with the industry as a whole moving toward higher strength, better flexibility, and longer service life.

I. Market Size and Growth Trends

From the perspective of market size, the hanger bolt industry maintains a steady growth trend. According to a survey by Hengzhou Chengsi, the global hanger bolt market size in 2024 is approximately 39.06 billion yuan, and it is expected to approach 48.92 billion yuan by 2031, with a compound annual growth rate (CAGR) of approximately 3.3% over the next six years. Meanwhile, the overall performance of China's fastener industry is strong — the domestic fastener market size exceeded 1.6 trillion yuan in 2024, with output exceeding 9.5 million tons, ranking as the world's largest producer.

From the perspective of product application areas, hanger bolts and flexible adapter plates mainly serve three major directions: new energy photovoltaic installations, building seismic brackets, and electromechanical pipeline support systems. Among them, the demand for high-performance connectors in new energy infrastructure is particularly prominent, with fast-growing requirements for corrosion-resistant and high-temperature-resistant fasteners in projects such as wind turbine towers, photovoltaic supports, and charging piles.

Regarding global construction fasteners, the market size for construction fasteners in 2024 is estimated to be approximately **US$98.7𝑏𝑖𝑙𝑙𝑖𝑜𝑛\ast \ast ,𝑎𝑛𝑑𝑖𝑠𝑒𝑥𝑝𝑒𝑐𝑡𝑒𝑑𝑡𝑜𝑔𝑟𝑜𝑤𝑡𝑜𝑈𝑆$billionandisexpectedtogrowtoUS142.3 billion by 2034, with a CAGR of 4.1%. This provides a broad market space for flexible adapter plates and hanger bolts.

II. Highlights of Technological Innovation in the Photovoltaic Field

In the field of solar roof mounting in 2024, the combination solution of flexible adapter plates and hanger bolts demonstrated significant technical advantages, with several companies launching innovative products designed for different roof types.

Angle‑adjustable flexible adapter technology — The ClickFit EVO series developed by Esdec (Netherlands) features a flexible adapter plate that can compensate for uneven roof surfaces, adapting to angles of up to 10 degrees. This effectively solves the installation difficulties of PV systems on corrugated metal roofs, slate roofs, and various other roof types. The product uses a smart clip‑in design that significantly reduces the number of components, increasing installation speed by up to 50%.

Pre‑assembled high‑efficiency installation solution — The adapter plate with hanger bolt set (PVM‑L‑03) launched by PVMOUNTS is specifically designed for corrugated fiber‑cement boards, trapezoidal metal sheets, and metal roofs. Manufactured from SUS 304 stainless steel, it provides excellent corrosion resistance. The product is available in lengths from 150mm to 300mm to suit different roof thicknesses. The double‑ended thread design allows one end to anchor into the roof beam and the other to connect to PV rails, while the EPDM sealing washer provides a reliable waterproof layer to prevent roof leakage.

Swiss precision products — The stainless steel hanger bolt with adapter plate set (M10×250mm / 4‑piece set) from NuaSol is made of SUS304 stainless steel, with adapter plate dimensions of 30mm×82mm and optimized hole patterns. Together with the EPDM sealing washer, it ensures long‑lasting use in all weather conditions. This product has been widely used in balcony PV systems and small PV power station installations in Europe.

III. Technological Evolution of Seismic Brackets and Hanger Bolts

3.1 In‑depth Research and Development of Prefabricated Supports and Hangers

In 2024, technological breakthroughs have been achieved in the field of seismic brackets. Prefabricated supports and hangers have been widely used in engineering projects, and research institutions have conducted systematic studies on them. Some researchers have carried out low‑cycle reciprocating loading tests on portal‑type supports and hangers to analyze the influence of seismic diagonal braces, seismic connectors, and joint connection types on their seismic performance.

The results show that: Specimens with bolted through‑connections exhibit better seismic performance than those relying on frictional or interlocking action. Seismic diagonal braces significantly improve the overall seismic performance of portal‑type supports and hangers; specimens with diagonal braces have better elastic stiffness, ultimate bearing capacity, yield bearing capacity, and energy dissipation capacity than those without diagonal braces.

3.2 Innovations in Seismic Bracket Products

Multiple patents for seismic brackets and fasteners were granted in 2024, highlighting the industry's strong focus on connection safety and seismic performance:

Hebei Yisen Fastener Manufacturing Co., Ltd. obtained a patent for a "Quick‑install elastic seismic support" (Announcement No. CN 221972728 U). This product adopts a clip‑in quick‑install design with anti‑slip grooves on the surface to effectively prevent sliding during installation and use. It also includes a sunshade plate design to reduce material damage and extend service life.

Guangdong Boya Industrial Co., Ltd. obtained a patent for a "High‑stability seismic support and hanger" (Announcement No. CN 221991490 U). This patent addresses the problem of elastic force attenuation after prolonged damping using a sealed piston, buffer sleeve, and oil reservoir chamber. It also achieves anti‑loosening locking of bolts through a combined structure of sliding rods, springs, toothed plates, and bolts.

Suzhou Hongyiyi Hardware Technology Co., Ltd. obtained a patent for a "Hardware fastener with seismic and anti‑loosening function" (Announcement No. CN 221942951 U), providing a systematic solution for fastener loosening under vibration conditions.

In addition, patents such as the "Seismic fastener connection structure" from Nantong Jingbo Technology Co., Ltd. (Announcement No. CN 222141751 U) and the "High‑strength seismic bolt" from Quzhou Tianli (Announcement No. CN 222045916 U) were also granted in 2024, collectively forming an increasingly complete patent landscape in this field.

IV. Standards and Policy Updates

In 2024, China issued several important technical standards and regulations in the field of hanger bolts and supports and hangers, actively promoting standardized industry development.

"Technical Specification for Prefabricated Supports and Hangers of Mechanical and Electrical Equipment in Civil Buildings" — This specification was officially released by the China Real Estate Association under number T/CREA 041-2024 and took effect on December 1, 2024, providing a unified technical basis for the design, construction, and acceptance of prefabricated supports and hangers.

"Technical Specification for Replacement of Suspenders of Arch Bridges" — This specification was approved by the China Association for Engineering Construction Standardization under number T/CECS 1546-2024 and came into effect on July 1, 2024. It provides detailed regulations in five aspects: suspender and anchorage systems, design, construction, construction monitoring, and quality inspection, standardizing material selection, design principles, and construction procedures for arch bridge suspenders.

"High strength large hexagon head bolt sets for steel structures" (GB/T 1231-2024) — This national standard was released in 2024 and will take effect on April 1, 2025. The new version adds M33 and M36 specifications and revises the dimensional and technical requirements for bolt sets, further expanding the application range of high‑strength bolts.

V. Global Trade Environment and Industry Challenges

Since the fourth quarter of 2024, China's fastener industry has faced new challenges in international trade. Australia, the United States, the European Union, and other countries and regions have frequently initiated anti‑dumping and countervailing investigations against Chinese fastener products. Key developments include:

The European Union initiated an anti‑dumping investigation on October 17, 2024, concerning headless screws originating in China (Notice No. C/2024/6209), covering CN codes 73181542 and 73181548. The dumping investigation period is from July 1, 2023, to June 30, 2024.

Australia initiated anti‑dumping and countervailing investigations in December 2024 against friction bolts imported from China, which are widely used in mining, tunnelling, and civil engineering projects.

The United States made its fourth sunset review final determination of anti‑dumping duties on non‑malleable cast iron pipe fittings from China, concluding that if the duties were revoked, the dumping margin would likely remain at 75.50%.

These trade frictions bring uncertainty to the export business of domestic fastener companies, but they also push enterprises to accelerate product structure upgrades and shift toward high‑value‑added products.