Aluminum Alloy Bolts And Plugs

1. Core Functions and Applications
Aluminum Alloy Bolts: Used in lightweight connections such as automotive bodies, aerospace structures, and electronic equipment housings. They must withstand tensile and shear loads while maintaining high-precision assembly.
Aluminum Alloy Plugs: Used for sealing holes (such as process holes in hydraulic/pneumatic systems), blocking heat dissipation channels, or decorative covers. They must balance sealing, corrosion resistance, and aesthetics.
2. Material Selection: Balancing Performance and Lightweight
5XXX Series Aluminum Alloys: A series of aluminum alloys with magnesium as the primary alloying element. They feature low density, high specific strength, and excellent formability and weldability. They are commonly used in automotive body panels.
6XXX Series Aluminum Alloys: A series of aluminum alloys primarily composed of aluminum, magnesium, and silicon, with additions of copper and iron. Optimized aging processes (such as precise temperature control and gradient cooling) can significantly enhance tensile and yield strengths.
7XXX series aluminum alloys: High-strength aluminum alloys primarily composed of aluminum and zinc, with other elements added. This alloy series is primarily used in the manufacture of large, complex structural components in the aerospace, automotive, and other fields.
3. Processing: Precision Forming and Threading
Cold Heading: Cold heading is suitable for mass production of standard bolts (e.g., M3-M12), offering high efficiency and material utilization.
Turning/Milling: CNC machine tools enable high-precision machining of external diameters, internal holes, and end faces, with tolerances up to ±0.05mm and surface roughness below Ra0.8.
Threading: Threads are tapped or rolled to ensure thread accuracy (e.g., 6H/6g), with gauges used to verify continuity.
Heat Treatment: Solution treatment enhances hardness and strength, annealing relieves machining stresses.
Surface Treatment: Anodizing improves corrosion and wear resistance, electrophoretic coating provides corrosion protection.
 4. Quality Control:
Dimensional Accuracy: Outer/Inner Diameter Tolerance ±0.05mm, Length Tolerance ±0.2mm, Thread Parameters (Major, Pitch, Minor Diameter) Comply with ISO Standards.
Surface Quality: Free of defects such as cracks, burrs, and scratches, with uniform electrophoretic coating thickness.
Mechanical Properties: Hardness, tensile strength, and shear strength tested.
Sealing Performance: Plugs must pass pressure tests (such as water/air pressure seal tests) to verify leak-free operation.
5. Design Optimization: Innovative Paths for Performance Improvement
Structural Optimization:
Bolts: Use rolled threads to enhance surface strength, design anti-loosening features (such as anti-loosening adhesive), and optimize head shapes (such as internal/external hexagonal) to improve wrench compatibility.
Screw Plugs: Add O-ring grooves to enhance sealing.
Process Optimization:
Precision Machining: Use CNC machine tools and grinders for high-precision machining, combined with online inspection to ensure dimensional consistency.