Building something strong? It starts with the right connections.  Our extensive selection of high-quality bolts ensures your projects are secure and reliable, from the ground up.   Don't compromise on strength. Whether you need the enhanced support of Hex Head Flange Bolts, the robust grip of Lag Bolts, or the specialized function of Wheel Studs or Anchor Bolts, we've got you covered.  Browse our catalog and find the connections that matter most. Click below to learn more: Products-Zhejiang Zhongrui Auto Parts Co., Ltd.

With over 38 years of experience, Zhejiang Zhongrui Auto Parts is your reliable source for high-quality fasteners. Our production facilities and skilled team ensure that every product meets excellent standards.   We specialize in: High-strength Bolts & Nuts, manufactured with precision using multi-station cold heading and hot forging processes. Customized solutions to meet your unique application needs. Surface Treatments, including Dacromet, galvanizing, and more, to enhance corrosion resistance.   Visit our booth at the 2025 China Yiwu International Auto And Motocycle Expo from April 7th-9th and let's explore how we may empower your business. Booth E1G13   Contact Info: +86-18858333555zrqiche@163.com

1. Currently, the standard parts on the market mainly include carbon steel, stainless steel, and copper. (1) Carbon steel. We distinguish low carbon steel, medium carbon steel high carbon steel, and alloy steel by the content of carbon in carbon steel material. 1. Low carbon steel C%≤0.25% is usually called A3 steel in China. Foreign countries are called 1008, 1015, 1018, 1022, etc. Mainly used for grade 4.8 bolts, grade 4 nuts, small screws, and other products without hardness requirements. (Note: The drill tail screw is mainly made of 1022 material.) 2. Medium carbon steel 0.25% 3. High carbon steel C%>0.45%. Currently not used in the market 4. Alloy steel: Add alloying elements to ordinary carbon steel to increase some special properties of steel: such as 35, 40 chromium molybdenum, SCM435, and 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, the main components are C, Si, Mn, P, S, Cr, and Mo. (2) Stainless steel. Performance Class: 45, 50, 60, 70, 80 Mainly divided into austenite (18%Cr, 8%Ni) with good heat resistance, good corrosion resistance, and good weldability. A1, A2, A4 Martensite and 13%Cr have poor corrosion resistance, high strength, and good wear resistance—C1, C2, and C4 ferritic stainless steels. 18%Cr has better upsetting and corrosion resistance than martensite. At present, the imported materials on the market are mainly Japanese products. According to the level, it is mainly divided into SUS302, SUS304 and SUS316. (3) Copper. Commonly used materials are brass...zinc-copper alloys. The market mainly uses H62, H65, and H68 copper as standard parts. 3. The influence of various elements in the material on the properties of steel: 1. Carbon (C): It improves the strength of steel parts, especially its heat treatment performance, but with the increase of carbon content, the plasticity and toughness decrease, and it will affect the cold heading performance and welding performance of steel parts. 2. Manganese (Mn): Improve the strength of steel and improve hardenability to a certain extent. That is, it increases the strength of hardening penetration during quenching, and manganese can also improve surface quality, but too much manganese is detrimental to ductility and weldability. And will affect the control of the coating during electroplating. 3. Nickel (Ni): Improves the strength of steel parts, improves the toughness at low temperatures, improves the resistance to atmospheric corrosion, and can ensure a stable heat treatment effect and reduce the effect of hydrogen embrittlement. 4. Chromium (Cr): It can improve hardenability, improve wear resistance, improve corrosion resistance, and is conducive to maintaining strength at high temperatures. 5. Molybdenum (Mo): It can help control hardenability, reduce the sensitivity of steel to temper brittleness, and have a great impact on improving tensile strength at high temperatures. 6. Boron (B): It can improve hardenability and help low-carbon steel to have the expected response to heat treatment. 7. Alum (V): refines austenite grains and improves toughness. 8. Silicon (Si): To ensure the strength of steel parts, appropriate content can improve the plasticity and toughness of steel parts. (2) The relationship between the main chemical composition and the properties of stainless steel. 1. Carbon C can increase hardness and strength, and excessive content will reduce its ductility and corrosion resistance 2. Chromium Cr can increase corrosion resistance, oxidation resistance, refined grains, increase strength, hardness, and wear resistance 3. Nickel Ni can increase high-temperature strength, and corrosion resistance and reduce the rate of cold work hardening 4. Molybdenum Mo increases the strength and has corrosion resistance to oxides and seawater

The automotive industry is constantly evolving, with innovations in design, materials, and engineering techniques pushing the boundaries of what's possible.  One such innovation that has gained significant traction in recent years is the use of hexagon head flange screw bolts.  These specialized fasteners are now playing a crucial role in enhancing the performance, safety, and reliability of vehicles. What Are Hexagon Head Flange Screw Bolts? Hexagon head flange screw bolts are a type of fastener that features a hexagonal head with a flange, or a flat, circular plate, beneath the head.  This design provides a larger bearing surface, which helps distribute the load more evenly and reduces the risk of the bolt head sinking into soft materials.### Benefits of Hexagon Head Flange Screw Bolts 1.  Increased Torque Resistance: The flange design of these bolts allows for higher torque to be applied without the risk of the fastener head deforming or damaging the surrounding material. 2.  Improved Load Distribution: The flange helps to distribute the clamping force more evenly, reducing stress concentrations and the potential for material failure. 3.  Enhanced Safety: In critical applications where safety is paramount, such as in automotive suspension systems or engine mounts, hexagon head flange screw bolts provide a reliable and secure connection. 4.  Versatility: These bolts are suitable for a wide range of applications, from general assembly to heavy-duty use in construction machinery and transportation vehicles. Applications in the Automotive Industry Hexagon head flange screw bolts have found their way into various automotive applications, including: - Engine Mounts: Ensuring a secure and stable connection between the engine and the vehicle chassis.- Suspension Systems: Providing a robust fastening solution for shock absorbers and other suspension components.- Braking Systems: Withstanding the high forces generated during braking, ensuring a safe and reliable connection.- Body and Chassis Assembly: Offering a strong and durable fastening solution for the vehicle's body panels and chassis components.

In the intricate and complex world of automotive engineering, it's easy to overlook the small but vital components that keep our vehicles running smoothly and safely.  Among these are the common automotive fasteners, the unsung heroes that play a crucial role in assembling and maintaining our cars, trucks, and motorcycles. 1.  Bolts and Nuts: The Backbone of Automotive Assembly Bolts and nuts are perhaps the common automotive fasteners.  They are used in a variety of applications, from engine assembly to suspension systems.  Made from strong materials like steel and aluminum, these fasteners are designed to withstand the rigors of daily driving and the stress of high-performance environments. 2.  Screws: Precision and Versatility Screws are another essential type of automotive fastener, offering precision and versatility in their application.  They are used in everything from securing trim pieces to attaching critical components within the engine bay.  The variety of screw types, such as flat head, Phillips, and socket head screws, each serve a specific purpose and are chosen based on the requirements of the application. 3.  Washers: The Buffers of Force Washers are thin, disc-shaped fasteners that are placed between a bolt or nut and the surface it's fastening.  They distribute the force exerted by the fastener, preventing damage to the joined materials and ensuring a secure fit.  Washers are commonly used in conjunction with automotive fasteners to maintain the integrity of the connection. 4.  Rivets: Permanent Connections Rivets are used in situations where a permanent connection is required.  Once installed, they cannot be removed without damaging the materials they join.  Rivets are commonly found in body panels, chassis construction, and other areas where a strong, unyielding bond is necessary. 5.  Studs and Threaded Rods: Lengthy Connections Studs and threaded rods are long, threaded fasteners used to join components that are spaced apart.  They are particularly useful in applications where a long connection is needed, such as attaching a wheel to a suspension hub or securing a large component to an engine block. 6.  Self-Tapping Screws: Easy Assembly Self-tapping screws are designed to create their threads in a pre-drilled hole, eliminating the need for a separate tapping process.  This feature makes them ideal for quick assembly and disassembly, often found in automotive interiors and exteriors. 7.  Retaining Rings and Clips: Securing Small Components Retaining rings and clips are small, yet critical fasteners used to secure components in place within tight spaces.  They are commonly found in engines, transmissions, and other areas where small parts need to be held securely without the use of larger fasteners.