Release time：2020-01-16 18:44 Browse：
### 1. **Material & Mechanical Properties**
- **SUS304 Stainless Steel**: Contains 18-20% chromium and 8-10.5% nickel, offering corrosion resistance in humid environments and mild chemicals.
- **Mechanical Strength**: Tensile strength ≥520 MPa, yield strength ≥205 MPa, and 40% elongation, making it ductile for precision assembly.
- **Heat Treatment**: Solution-annealed at 1,050–1,100°C to ensure uniform microstructure and non-magnetic properties (ideal for electronic applications).
### 2. **Precision Dimensions**
- **M3x25mm Specification**: 3mm diameter with 25mm full-threaded length, conforming to ISO 4762 for hex socket cap screws.
- **Head Design**: Cylindrical cup head with 5.5mm diameter, 3mm height, and 2.5mm internal hex socket (drive size), allowing high-torque engagement with socket wrenches.
- **Thread Details**: Metric fine thread (M3x0.5 pitch) with 6g tolerance, ensuring precise fit and minimal play in mating components.
### 3. **Black Surface Treatments**
- **Black Oxide Coating**: Thin (0.5–1.5μm) magnetic layer enhancing corrosion resistance to 200–500 hours in salt spray tests, suitable for indoor machinery.
- **PVD TiCN Coating**: 2–3μm hard coating (2,000–2,500 HV) offering 1,000+ hours of salt spray resistance, ideal for high-wear applications like robotics.
- **Black Zinc-Nickel Plating**: 8–12μm thick layer with 1,000+ hours of salt spray protection, suitable for outdoor or automotive use.
### 4. **Customization Options**
- **Non-Standard Lengths**: Available from 10–100mm in 1mm increments for deep mounting or specialized assemblies.
- **Thread Modifications**: Left-hand threads, UNC/UNF inch threads, or self-locking designs (nylon inserts) for vibration-prone environments.
- **Markings & Coatings**: Laser-engraved logos, batch codes, or custom PTFE coatings for low-friction applications (e.g., sliding mechanisms).
### 5. **Manufacturing Processes**
- **Cold Forging**: Forms the head with grain flow alignment, improving fatigue strength by 30% compared to machined parts.
- **Thread Rolling**: Non-cutting process creates stronger threads with 25% higher fatigue life than traditional threading.
- **Quality Control**: 100% inspection for thread go/no-go gauging, head dimensions, and surface finish (Ra ≤1.6μm).
### 6. **Industrial Applications**
- **Microelectronics**: Mounting PCBs, semiconductor equipment, and ESD-sensitive components (with PVD coatings).
- **Medical Devices**: Surgical tools and diagnostic machinery (passivated SUS304 for biocompatibility).
- **Automotive**: Engine control units, sensors, and vibration-resistant mounts (black Zn-Ni plating).
- **Aerospace**: Lightweight, non-magnetic components for avionics and satellite assemblies.
### 7. **Wholesale & Logistics**
- **Inventory**: 50,000+ standard M3x25mm black oxide screws in stock for same-day shipping.
- **Packaging**: Anti-corrosion poly bags with VCI film, 1,000 pieces per carton, palletized for bulk orders (10,000+ pieces).
- **Lead Times**: 1–3 days for standard orders; 10–15 days for custom coatings or lengths.
### 8. **Technical Advantages**
- **Anti-Slip Features**: Knurled shanks (on request) and toothed under-head designs prevent rotational slip in soft materials.
- **Torque Efficiency**: Internal hex drive allows 30% higher torque than Phillips heads, reducing assembly time.
- **Corrosion Resistance**: 304 stainless steel with black coatings withstands 500–1,500 hours of salt spray, ideal for harsh environments.
### 9. **Regulatory Compliance**
- **Standards**: Meets ISO 4762, ISO 9001, and RoHS 2.0; CE marked for structural use in the EU.
- **Certifications**: Material test reports (MTRs) available, confirming chemical composition and mechanical properties.
### 10. **Installation Tips**
- Use a 2.5mm hex socket driver with torque control (1.2–1.6 Nm for dry threads) to avoid stripping.
- Apply anti-seize compound when fixing to aluminum to prevent galvanic corrosion.
- In high-temperature applications (over 250°C), choose PVD coatings for stability.
