Stainless Steel Carriage Bolts

In harsh environments such as outdoor construction, marine environments, and chemical equipment, fastener corrosion has always been a major industry problem. Even with surface treatment, stainless steel carriage bolts are prone to rusting and failure in salt spray, humid, or chemical environments, which not only affects the stability of the connection but also significantly increases subsequent maintenance costs. Furthermore, traditional fasteners are cumbersome to install, making operation extremely inconvenient in confined spaces.

We are a source factory with over 15 years of experience in fastener research, development, and manufacturing, serving global construction contractors, railing manufacturers, and marine engineering companies for many years. Based on our deep understanding of these practical working conditions, we know that fasteners in harsh environments must be both corrosion-resistant and easy to install and secure.

Core Technological Advantages

1. Excellent Corrosion Resistance, Suitable for Multiple Harsh Environments

304 Stainless Steel (A2-70) Model: Possesses excellent oxidation and water corrosion resistance, easily handling most outdoor environments and general industrial scenarios. Whether it's outdoor building railings or equipment fixing in ordinary humid workshops, it can maintain stable performance for a long time and is not prone to rusting.

316 Stainless Steel (A4-80) Model: The core advantage is the inclusion of molybdenum, which significantly enhances its resistance to chloride corrosion. In marine environments, high-salt spray areas, and strong corrosive environments such as chemical equipment, 316 material can effectively resist the erosion of seawater and chemical media, making it the preferred fastener for these harsh environments, with a service life far exceeding that of ordinary stainless steel.

Both materials can be selected as needed. Whether it's a regular outdoor scenario or a special working condition with strong corrosion, we can provide customers with precisely matched solutions, solving the corrosion problem from the root and reducing maintenance costs.

2. Unique Square Neck Anti-loosening Design, Efficient and Secure Installation

Self-locking function: The square neck below the bolt head is the core anti-loosening guarantee. When the nut is tightened, the square neck will firmly lock into the hole wall of the connected part, generating strong friction, preventing the bolt shaft from rotating with the nut, avoiding loosening and stripping caused by vibration, and ensuring long-term stable connection. Easy and time-saving installation: During installation, only one wrench is needed to tighten the nut, eliminating the need for a second wrench to hold the bolt on the other side. This feature is particularly advantageous in high-altitude work, confined spaces, or situations requiring single-sided operation, significantly improving construction efficiency and saving labor costs.

3. Aesthetically pleasing and safe head design, combining practicality and protection

Featuring a round head (mushroom head) design that conforms to DIN 603 and GB/T 14 standards, the head is smooth and rounded, without sharp edges. It will not snag clothing or scratch skin during use, ensuring high safety, making it particularly suitable for amusement facilities, park benches, livestock fences, and other scenarios involving frequent contact with people or animals.

The head has no screwdriver slot, providing a certain degree of anti-theft and anti-tampering functionality. Unauthorized personnel cannot easily remove it with ordinary tools, better protecting the safety of outdoor public facilities, ship equipment, and other assets.

Core Technical Parameters

Typical Application Scenarios

With years of industry service experience, our stainless steel carriage bolts have been successfully applied in various demanding environments, becoming a trusted choice for numerous customers:

1. Marine and Shipbuilding Engineering: Used for connecting ship decks, railings, and dock facilities. The 316 material offers excellent salt spray corrosion resistance, ensuring long-term use in seawater without rusting and guaranteeing the stability of connections in ships and dock facilities.

2. Construction and Wood Structures: Used for connecting heavy timber beams, villa exterior walls, and terrace flooring. The square neck design perfectly fits into wood, providing a secure and aesthetically pleasing connection. The 304 stainless steel material resists corrosion from humid outdoor environments, extending the service life of buildings.

3. Infrastructure and Guardrails: Used for highway guardrails, bridge crash barriers, and municipal fences. Its anti-theft and anti-loosening features effectively prevent bolts from loosening or being maliciously removed, ensuring the long-term safety and stability of public facilities.

4. Agriculture and Animal Husbandry: Used for constructing pasture fences and livestock sheds. The stainless steel material resists corrosion from animal waste and humid environments, resulting in a long service life and significantly reducing maintenance costs and workload for farmers.

Company Strength and Quality Assurance

We are Ningbo Gangtong Zheli Fasteners Co., Ltd. Since our establishment in 2001, we have built a mature R&D, production, and sales system for fasteners. Our factory is located in the Zhenhai Chemical Industrial Zone of Ningbo, and our headquarters and foreign trade sales department are located in the Ningbo Jiangdong Eastern Business Center.  Our factory covers an area of 15,000 square meters, with a stable monthly production capacity of 2,000 tons and annual sales exceeding US$15 million. The company is equipped with a professional R&D team, a full-process supply chain management system, and large-scale warehousing facilities. We specialize in the production of various fasteners and can provide integrated MRO procurement and distribution services for metal fasteners, comprehensively meeting the diverse procurement needs of our customers.

In the fastener industry, quality is paramount. We ensure the reliability and durability of every stainless steel carriage bolts through rigorous control throughout the entire process:  During raw material warehousing, each batch of stainless steel raw materials undergoes spectral analysis to precisely control the chemical composition, eliminating material defects from the source; during production, the dimensional accuracy and thread quality of the bolts are fully inspected to prevent unqualified semi-finished products from entering the next process; in the finished product stage, rigorous salt spray tests (up to 500 hours or more), tensile tests, and other tests are conducted to comprehensively verify corrosion resistance and mechanical strength. The company fully implements the ISO 9001 quality management system standard and can provide material certificates (MTC) according to customer requirements, ensuring that the product's chemical composition and mechanical properties fully meet the standards. At the same time, the products comply with the RoHS environmental protection directive, containing no harmful substances and being harmless to the environment and human body.

Our product range is extensive, covering heavy-duty hexagonal bolts, heavy-duty hexagonal nuts, threaded rods, studs, washers, screws, etc., with materials including carbon steel, alloy steel, and stainless steel. We strictly adhere to international standards such as DIN, ISO, EN, JIS, ASTM/ANSI/ASME/SAE, BS, and AS. Our products are exported to North America, Europe, Australia, Southeast Asia, the Middle East, Latin America, and many other regions, and are suitable for various fields such as building steel structures, bridges, oil pipelines, mechanical equipment, ships, and railways.

Reasons to Choose Us

1. Direct supply from the source factory, superior quality and price: As a physical manufacturer located in Ningbo, the fastener capital of China, we possess advanced cold heading, heat treatment, and testing equipment, enabling us to achieve independent production throughout the entire process from raw materials to finished products. Without intermediaries, we can provide customers with highly competitive factory prices, while controlling quality throughout the process. We have sufficient stock of standard specifications and can quickly respond to delivery needs.

2. Technology-driven, rapid response: Our engineering team has rich experience in the research and development and production of stainless steel fasteners, and is familiar with the standard requirements of different regions worldwide. We can provide professional non-standard customization (OEM/ODM) services based on drawings or samples provided by customers; we can quickly respond to and provide targeted solutions to technical problems encountered by customers during use. 3. Global Service Experience, Hassle-Free Cooperation: Our products have been exported to North America, Europe, Australia, and Southeast Asia, and we have a comprehensive logistics and after-sales service system. We can accurately match the procurement needs of global customers and are committed to establishing long-term and stable cooperative relationships with our clients.