Release time：2020-01-16 18:44 Browse：
### 1. **Standard Compliance: DIN912** - **Origin and Significance**: DIN912 is a technical standard developed by the Deutsches Institut für Normung (DIN), the German Institute for Standardization. This standard is widely recognized and adhered to in Germany, Europe, and globally. It precisely defines the dimensions, material properties, and finish requirements for hexagon socket head cap screws. By conforming to DIN912, these screws ensure compatibility and interchangeability across different manufacturers and applications. For example, in a large - scale industrial project where components from multiple suppliers are used, DIN912 - compliant screws can be easily integrated, streamlining the assembly process. - **Dimensions and Tolerances**: The standard covers a wide range of sizes, with thread diameters typically ranging from as small as M1.6 to as large as M64 in Grade A metric products. The thread tolerance is generally set at 6g for most grades, except for the 12.9 grade, which has a more precise 5g6g tolerance. This tight tolerance control guarantees that the screws fit snugly into threaded holes, providing a secure and reliable connection. The head height, diameter, and socket dimensions are also specified in detail, ensuring proper engagement with hex keys or Allen wrenches. ### 2. **Screw Design: Hexagon Socket Head Cap** - **Cylindrical Head**: The cap screw features a cylindrical head design. This shape offers a smooth and low - profile appearance, which is beneficial in applications where a flush or unobtrusive finish is desired. For instance, in the assembly of furniture or electronic devices, the cylindrical head can be countersunk or recessed, giving a clean and professional look. The head also provides a large bearing surface area when tightened, distributing the clamping force evenly across the fastened materials and preventing damage or deformation. - **Internal Hexagonal Socket**: The internal hexagonal socket, also known as an Allen socket, is designed to be driven by a hexagon wrench or Allen key. This drive system allows for a high level of torque application in a compact space. The six - sided socket provides a secure grip, minimizing the risk of slippage during installation or removal. In machinery or equipment with limited access points, the ability to use a hex key to tighten or loosen the screw is extremely convenient. Additionally, the socket design provides a tamper - resistant feature, as special tools are required to operate the screw. ### 3. **Washer Combination: Spring and Flat Washers** - **Spring Washer Function**: The pre - assembled spring washer plays a crucial role in ensuring the long - term stability of the connection. It provides a continuous, elastic force against the nut or the fastened surface. In applications where there is vibration or dynamic loading, such as in automotive engines or industrial machinery, the spring washer helps to prevent the screw from loosening over time. The spring action compensates for any minor movement or expansion and contraction of the materials being fastened, maintaining the clamping force and the integrity of the joint. - **Flat Washer Function**: The flat washer is placed between the spring washer and the surface of the material being fastened. Its primary function is to distribute the clamping force more evenly. When the screw is tightened, the flat washer spreads the load over a larger area, reducing the risk of indentation or damage to soft materials like wood, plastic, or thin metal sheets. It also helps to minimize stress concentration points around the screw hole, which can lead to fatigue failure in the long run. In addition, the flat washer can act as a spacer in some cases, ensuring proper alignment and clearance between components. ### 4. **Finish: Black Screws** - **Possible Finish Types**: The black finish on these screws could be achieved through several methods. One common method is black oxide treatment, where the screw is chemically treated to form a thin, black oxide layer on the surface. This oxide layer provides a certain level of corrosion resistance by acting as a barrier between the metal substrate and the environment. Another option could be black zinc plating, which combines the corrosion - resistant properties of zinc with a black appearance. Some manufacturers may also use phosphate coatings with a black pigment or other specialized black - colored coatings. - **Benefits of the Black Finish**: The black finish not only provides an aesthetically pleasing, low - key appearance but also offers practical advantages. In terms of corrosion resistance, it can protect the screw from rust and oxidation in moderately corrosive environments. In applications where the screw is exposed to moisture, such as in outdoor equipment or humid industrial settings, the black finish can significantly extend the lifespan of the screw. Additionally, the black color can help the screw blend in with its surroundings, which is useful in applications where a more discrete or uniform look is desired, such as in furniture or decorative fixtures. ### 5. **Applications** - **Industrial Machinery**: In industrial machinery, these DIN912 hexagon socket head cap screws with spring and flat washers are used to secure various components. They can fasten gears, pulleys, and shafts in motors, pumps, and compressors. The combination of the high - strength screw, the anti - loosening spring washer, and the load - distributing flat washer ensures a reliable connection that can withstand the high - torque and vibration conditions present in industrial machinery. - **Automotive Industry**: In the automotive industry, these screws are used in engine assemblies, chassis components, and interior fittings. For example, they can be used to attach engine brackets, suspension components, or dashboard panels. The black finish can match the overall aesthetic of the vehicle's interior or engine bay, while the DIN912 standard ensures that the screws meet the high - quality and safety requirements of the automotive industry. - **Electronics and Appliances**: In the electronics and appliance sectors, the low - profile design of the hexagon socket head cap screws is highly desirable. They are used to assemble electronic enclosures, circuit boards, and small - scale mechanical components in appliances. The precision of the DIN912 - compliant screws and the added stability provided by the washer combination are crucial for ensuring the proper functioning and durability of these products, especially in devices that may be subject to vibration or movement during normal use.
