Release time：2020-01-16 18:44 Browse：
### 1. **Core Material: Carbon Steel for Strength & Durability** These hex flange bolts are manufactured from high-grade carbon steel (typically grades like 1045, 1018, or SAE J429 Grade 5), selected for its optimal balance of mechanical performance and cost-effectiveness. - **Tensile Strength**: Carbon steel delivers reliable tensile strength (ranging from 500–900 MPa, depending on the grade), enabling it to withstand medium to heavy-duty clamping forces—critical for applications like securing industrial machinery frames, automotive chassis components, or heavy equipment bases. - **Load-Bearing Capacity**: The material’s inherent rigidity resists shear stress and pull-out forces, ensuring the bolt maintains a secure hold even under repeated use or static loads (e.g., mounting HVAC units to metal brackets). - **Machinability**: Carbon steel’s easy machinability allows for precise shaping of the hex flange head, serrated underside, and threads, ensuring consistent quality across batches. ### 2. **Black Oxide Coating: Dual Protection & Functional Benefits** The bolts undergo a **black oxide treatment** (a chemical conversion process, also known as “hot blackening” or “bluing”), which creates a thin, adherent iron oxide layer (primarily magnetite, Fe₃O₄) on the surface. This coating offers multiple advantages: - **Corrosion Resistance**: While not as robust as galvanization or stainless steel, the black oxide layer acts as a barrier against mild moisture, dust, and atmospheric oxidation. It’s ideal for indoor, dry, or low-humidity environments (e.g., workshop tool stands, warehouse shelving, or indoor machinery) where heavy corrosion risks are minimal but basic rust protection is needed. - **Reduced Friction & Improved Installation**: The oxide layer has slight lubricating properties, reducing friction between the bolt’s threads and the mating nut/hole during installation. This minimizes “cross-threading” (damaged threads from misalignment) and makes tightening smoother, even with manual wrenches or power tools. - **Aesthetic & Practical Finish**: The deep, uniform black color gives the bolts a professional, industrial look that hides minor scratches or handling marks—suitable for visible applications like furniture hardware or equipment panels. Additionally, the non-reflective surface reduces glare, which is useful in precision settings (e.g., laboratory equipment) where light reflection could interfere with operations. - **Compatibility with Additives**: For enhanced protection, the black oxide layer can be post-treated with oil, wax, or a sealant (common in automotive or marine sub-assemblies) to boost corrosion resistance further without compromising the coating’s adhesion. ### 3. **Engineered Design: Hex Flange Head + Serrated Underside** The bolt’s design is optimized for ease of use, vibration resistance, and surface protection—eliminating the need for separate washers and improving overall fastening reliability: - **Hex Flange Head**: - **Hexagonal Head**: The six-sided head is compatible with standard hex wrenches, socket sets, and power tools (e.g., impact drivers), allowing for high-torque installation. The head’s sharp edges prevent slippage (even with worn tools), ensuring the bolt is tightened to the required torque specification. - **Integrated Flange**: The flange (a wide, flat, washer-like ring attached to the base of the head) serves three key purposes: 1. **Distributes Clamping Force**: Spreads pressure evenly across the mating surface, preventing indentation or damage to soft materials (e.g., plastic housings, thin sheet metal, or wood). 2. **Eliminates Separate Washers**: Saves time during assembly (no need to handle extra parts) and reduces the risk of washer loss or misalignment. 3. **Enhances Stability**: The flange’s large contact area reduces the chance of the bolt “tilting” during installation, ensuring the thread engagement remains straight. - **Serrated Underside**: The bottom of the flange features **radial or concentric serrations** (small, sharp, tooth-like ridges). When the bolt is tightened, these serrations dig into the surface of the mating part (e.g., a metal bracket or chassis), creating a mechanical lock that resists loosening from vibration or thermal expansion/contraction. This makes the bolts ideal for dynamic applications: - Automotive: Securing engine mounts, suspension components, or exhaust brackets (where engine vibration is constant). - Power Tools: Fastening motor housings or rotating parts (where high-speed vibration could loosen standard bolts). - Industrial Machinery: Mounting pumps, compressors, or conveyor belts (where operational vibration is common). ### 4. **Thread Performance: Extended Life Through Precision Engineering** The bolts’ threads are designed and manufactured to maximize longevity, reduce wear, and ensure consistent performance over time: - **Precision Thread Formation**: Threads are created via **roll threading** (a cold-forming process) rather than cutting, which strengthens the thread profile by work-hardening the carbon steel. Rolled threads have smoother surfaces, tighter tolerances (typically meeting ISO 4H or UNC 2A standards), and no sharp edges—reducing friction during installation and minimizing wear on both the bolt and the mating nut/hole. - **Wear & Galling Resistance**: The combination of carbon steel’s hardness and the black oxide coating reduces **thread galling** (a common issue where metal surfaces seize together due to friction). This is critical for applications requiring repeated disassembly/assembly (e.g., maintenance on machinery or automotive parts), as it prevents thread damage that would render the bolt unusable. - **Consistent Engagement**: Tight thread tolerances ensure the bolt mates perfectly with standard nuts or tapped holes, avoiding “loose” threads (which reduce clamping force) or “tight” threads (which cause installation difficulty). This consistency also means the bolts can be used interchangeably across batches, simplifying inventory management for manufacturers or contractors. - **Corrosion Protection for Threads**: The black oxide coating penetrates the thread crevices, protecting even hard-to-reach areas from rust. This prevents thread degradation (e.g., rust buildup that jams the bolt) and extends the bolt’s usable life in humid or dusty environments. ### 5. **Application Versatility & Practical Advantages** These black oxide-coated carbon steel hex flange bolts are versatile enough to suit a wide range of industrial, automotive, and general hardware needs: - **Industrial Applications**: Securing machinery frames, conveyor systems, manufacturing equipment, or storage racks—leveraging carbon steel’s strength and the serrated flange’s anti-vibration grip. - **Automotive Aftermarket & Repair**: Fastening engine components, brake calipers, or body panels—where black oxide’s corrosion resistance and extended thread life meet under-hood demands (e.g., exposure to oil or moderate moisture). - **DIY & Home Improvement**: Assembling furniture, installing shelving, or mounting fixtures—no need for washers, making projects faster and more straightforward. - **Commercial Equipment**: Mounting cash registers, display cases, or office machinery—where the black finish complements professional aesthetics and the hex head allows for easy maintenance. In summary, these bolts combine the strength of carbon steel, the protection of black oxide, the convenience of an integrated flange, and the reliability of serrated anti-vibration design—making them a cost-effective, long-lasting solution for medium-load, vibration-prone fastening tasks.
