As a fastener fixed on workpieces through pressure riveting, press-in studs are widely used in different industries due to their convenient installation and firm connection. However, their application scenarios and technical requirements vary significantly across industries. The differences are analyzed below from three aspects: industry application characteristics, material and specification differences, and performance requirements:
I. Electronics/Electrical Industry
Application Scenarios
- Product casing assembly: Connecting metal casings of laptops, mobile phones, and home appliances (refrigerators, air conditioners) with internal circuit boards and brackets.
- Panel fixation: Embedding screw holes in displays and control panels for easy disassembly and maintenance.
- Heat sink connection: Securing heat sinks, fan brackets, etc., while ensuring conductivity and heat dissipation.
Characteristics and Requirements
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Materials:
- Stainless steel (SUS304) or aluminum alloy is commonly used for corrosion resistance and conductivity (e.g., grounding needs).
- Copper is sometimes used for high-conductivity electronic components.
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Specifications:
- Mostly M2–M5 in size, with stud heights typically ≤10mm to fit thin and lightweight products.
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Key Performance:
- High precision: Must match circuit board holes accurately to avoid interfering with internal components.
- Surface treatment: Nickel or gold plating is often used to enhance oxidation resistance and conductivity.
- Vibration resistance: Must pass drop and vibration tests to prevent loosening and short circuits.
II. Automotive Manufacturing Industry
Application Scenarios
- Body structure connection: Fixing car doors, dashboards, and seat brackets as an alternative to traditional welding.
- Chassis and component installation: Quick assembly of suspension systems, battery packs, and wiring brackets.
- Interior fixation: Concealed connection of roof linings, trim panels, and airbag modules.
Characteristics and Requirements
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Materials:
- Carbon steel (e.g., low-carbon steel B1866) or stainless steel is mainstream, offering high strength and moderate cost.
- Alloy steel (e.g., 35# steel) may be used in high-strength chassis applications.
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Specifications:
- Mostly M4–M8 in size, with larger stud heights (10–20mm) to withstand heavy loads.
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Key Performance:
- Fatigue resistance: Must pass salt spray tests (≥500 hours) and vibration fatigue tests (simulating complex road conditions).
- High-temperature resistance: Heat-resistant coatings (e.g., Dacromet) are required for high-temperature areas like engine compartments.
- Installation efficiency: Compatible with automated press-in equipment for high-speed automotive production lines.
III. Aerospace/Rail Transit Industry
Application Scenarios
- Aircraft structure connection: Lightweight fixation of fuselage skins, cabin doors, and avionics.
- High-speed rail/metro car assembly: High-strength connection of roof air conditioners, seat skeletons, and cable trays.
Characteristics and Requirements
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Materials:
- Titanium alloy or aviation-grade aluminum alloy (e.g., 7075-T6) is preferred for lightweight and high-strength needs.
- Stainless steel (e.g., 316L) is used in high-corrosion environments (e.g., coastal route aircraft).
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Specifications:
- Mostly imperial threads (e.g., #4-40, M3.5) or non-standard custom sizes, with smooth, burr-free surfaces.
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Key Performance:
- Extreme environment adaptability: Resistance to high/low temperatures (-60°C~+200°C) and impact (e.g., aircraft turbulence).
- Reliability certification: Must comply with aerospace industry standards (e.g., AS9100), with traceable production batches.
- Anti-loosening design: Use lock threads or anti-loosening coatings to prevent loosening at high altitudes or high speeds.
IV. Medical Device Industry
Application Scenarios
- Medical equipment casing assembly: Connecting metal frames of CT machines, operating tables, and monitors.
- Implantable devices: Micro-stud connections in some orthopedic implants (e.g., spinal fixation systems) requiring biocompatibility.
Characteristics and Requirements
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Materials:
- Must use medical-grade stainless steel (316L) or titanium alloy, compliant with ISO 13485 medical standards.
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Specifications:
- Very small sizes (e.g., M1.6–M3), with stud heights ≤5mm for precision instruments.
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Key Performance:
- Cleanliness: Must pass sterile cleaning and sterilization (e.g., ethylene oxide sterilization).
- Surface roughness: Ra ≤0.8μm to prevent bacterial adhesion or operator injury.
- Non-magnetic: Studs used near MRI equipment must be completely non-magnetic (e.g., titanium alloy).
V. Furniture/Architectural Decoration Industry
Application Scenarios
- Furniture hardware connection: Fixing metal tables, chairs, and cabinets as an alternative to traditional screw drilling.
- Building curtain wall installation: Quick assembly of aluminum alloy curtain walls and steel structure keels.
Characteristics and Requirements
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Materials:
- Mostly carbon steel (galvanized or powder-coated) for low cost and daily corrosion resistance.
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Specifications:
- Larger sizes (M6–M10), with stud heights customized for panel thickness (commonly 15–30mm).
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Key Performance:
- Installation convenience: Supports manual tool press-in for on-site construction.