Release time：2020-01-16 18:44 Browse：
### 1. **Specifications & Dimensions** - **Size**: 3/8 inch diameter (imperial standard), with a hexagonal flange head integrating a built-in washer to distribute clamping force. - **Drive Type**: 12-point hex flange design, offering twice the contact surfaces of standard hex heads for enhanced torque application and reduced tool slippage in tight spaces. ### 2. **Strength & Standards Compliance** - **Grade 10.9**: High-tensile strength (tensile strength ≥1040MPa, yield strength ≥900MPa) achieved via heat-treated alloy steel (e.g., 42CrMo), suitable for heavy-load, high-stress applications. - **Certifications**: Conforms to ISO 4162 (hexagonal flange bolts) and DIN 9621 (high-strength mechanical fasteners), ensuring global dimensional and performance consistency. ### 3. **Surface Treatment: Black Oxide** - **Coating Process**: Chemical black oxide finish (Fe₃O₄ layer, 0.5–1.5μm thick) provides mild corrosion resistance, reduces light reflection, and improves lubricity during installation. - **Benefits**: Maintains thread precision, avoids galling, and offers a sleek, industrial aesthetic ideal for visible or machinery applications. ### 4. **Design Advantages** - **Integral Flange**: Eliminates the need for separate washers, simplifies assembly, and prevents damage to soft materials (e.g., aluminum, plastic) by spreading pressure evenly. - **12-Point Drive**: Enables secure tightening with 12-point sockets or wrenches, even with partial tool engagement—critical for high-torque scenarios in automotive or industrial machinery. ### 5. **Applications** - **Heavy Machinery**: Securing engine blocks, gearboxes, or structural brackets in construction equipment, agricultural machinery, or industrial presses. - **Automotive & Aerospace**: High-stress components like suspension systems, chassis mounts, or aircraft fittings requiring Grade 10.9 strength. - **Vibration-Prone Environments**: Flange and 12-point design resist loosening under cyclic loads, suitable for pumps, generators, or railway components. ### 6. **Manufacturing & Quality** - **Production**: Cold-headed forging with rolled threads (improves fatigue resistance) and heat-treated (quenched and tempered) to achieve Grade 10.9 hardness (32–39 HRC). - **Quality Checks**: Thread gauging (6g tolerance), tensile testing, and coating adhesion verification to meet ISO/DIN standards. ### 7. **Installation Notes** - Compatible with 12-point sockets/wrenches; use anti-seize compound in high-temperature applications to prevent seizing. - Ideal for applications where high strength, space efficiency, and corrosion resistance (mild) are critical.
