Release time：2020-01-16 18:44 Browse：
Extended automotive bolts (auto industry extended bolts) are widely used in the automotive sector and must meet several strict requirements to ensure safety, reliability, and performance. Here are the main requirements for extended automotive bolts:
High-Strength Steel: Extended automotive bolts are typically made of high-strength alloy steel (such as carbon steel, alloy steel, or martensitic steel) or stainless steel to ensure bolt strength and durability under high loads and stress. Common grades include 10.9, 12.9, or other specific strength grades.
Corrosion Resistance: Automotive bolts need to withstand harsh environments, such as moisture and salt, so they must have strong corrosion resistance. Surface treatments like zinc plating, nickel plating, or other corrosion-resistant coatings are typically applied.
Tolerance Requirements: The dimensions (including length, diameter, and thread accuracy) of extended bolts must strictly adhere to standard tolerances. Common standards include ISO 888 (bolt specifications), DIN 933 (hex bolts), and more.
Standardization of Length and Diameter: The length of the extended bolt is usually determined based on specific design requirements to ensure a precise fit and prevent connection failure due to overly long or short bolts.
Corrosion Protection: Due to automotive applications in harsh environments, bolts usually undergo plating treatments (such as zinc, nickel plating, or hot-dip galvanizing) to improve their corrosion resistance.
Surface Smoothness: Surface treatment not only protects against corrosion but also ensures a smooth surface to prevent defects from affecting the assembly quality.
Tensile and Shear Strength: Extended bolts must possess adequate tensile and shear strength to ensure they do not break or deform under stress.
Fatigue Testing: Given that automotive applications involve long-term vibrations and loads, extended bolts must undergo fatigue testing to ensure durability and prevent failure over time.
Anti-Loosening Design: To prevent the bolts from loosening due to vibrations or long-term use, many extended bolts are equipped with anti-loosening features, such as locking washers or nylon insert nuts, to ensure secure fastening.
Locking Mechanism: Some bolts incorporate self-locking threads or coatings to enhance anti-loosening performance.
Weld Strength: Some automotive bolts may require welding to other components, which necessitates a sufficiently strong weld to maintain a stable connection.
Welding Compatibility: The bolt must be compatible with the materials being welded to prevent corrosion or weakening of the connection.
Environmental Requirements: As environmental regulations become more stringent, extended bolts must be manufactured without harmful substances (such as lead, cadmium) and should comply with environmental standards such as REACH and RoHS.
Safety Certifications: Many automotive manufacturers require bolts to meet specific quality and safety standards, such as ISO/TS 16949, to ensure the bolts' quality and safety.
Consistency with Standards: Bolts must be designed and manufactured according to international or industry standards such as ISO 4014, DIN 933, SAE J429, etc., to ensure compatibility with automotive parts.
Model-Specific Customization: Different vehicle models may have varying bolt specifications and performance requirements, so extended bolts should be customized based on the specific needs of the vehicle.
