8.8 Grade Zinc Plated Industrial DIN251 Hexagon Socket Flange Head Allen Screw
DIN 251 hexagon socket flange head machine screws are German DIN standard specialized fasteners engineered for industrial mechanical fastening. Renowned for their integrated anti-loosening structure, high connection stability and standardized dimensional design, these screws are a mainstream choice for medium and high-load fastening scenarios. The one-piece hexagon socket drive and flange head structure eliminates the need for additional washers in assembly. Paired with 8.8 grade mechanical performance and zinc-plated anti-corrosion treatment, DIN 251 screws are widely adopted in various industrial assembly fields with strict requirements for connection firmness and installation efficiency.
- Integrated structure saves assembly time: The flange head replaces traditional flat washer and spring washer combinations, reducing assembly parts and improving fastening efficiency
- Strong anti-loosening performance: Flange surface features anti-slip serrations (optional for standard models) to prevent loosening from mechanical vibration, ensuring long-term connection stability
- Wide compatibility: Standardized DIN 251 dimensions cover mainstream metric thread specifications (M3-M24), adapting to various industrial workpiece and equipment fastening needs
- Easy operation: Hexagon socket drive compatible with universal standard hexagon socket wrenches, requiring no special tools and suitable for narrow, confined installation spaces
DIN 251 8.8 grade zinc-plated hexagon socket flange head machine screws are versatile industrial fasteners widely used in automobile manufacturing, construction machinery, machine tool equipment, sheet metal cabinet production, electrical and electronic equipment, hydraulic and pneumatic components, and automation equipment assembly. Typical applications include engine component fastening, gearbox assembly, sheet metal cabinet connection, hydraulic cylinder fixed installation, electrical panel mounting, and engineering machinery structural part fastening. These are the preferred fasteners for mechanical scenarios requiring high connection stability, anti-loosening performance and assembly efficiency.
| d | M3 | M4 | M5 | M6 | M8 | M10 |
|---|---|---|---|---|---|---|
| P | 0.5 | 0.7 | 0.8 | 1 | 1.25 | 1.5 |
| dk min | 5.2 | 6.78 | 7.72 | 9.7 | 12.7 | 15.7 |
| dk max | 5.5 | 7 | 8 | 10 | 13 | 16 |
| k min | 2.75 | 3.82 | 4.82 | 5.7 | 7.7 | 9.7 |
| k max | 3 | 4 | 5 | 6 | 8 | 10 |
| dc min | 6.7 | 8.8 | 10.7 | 12.3 | 15.7 | 19.7 |
| dc max | 7 | 9 | 11 | 12.6 | 16 | 20 |
| c min | 0.8 | 1 | 1 | 1.3 | 1.8 | 2 |
| c max | 1 | 1.2 | 1.2 | 1.5 | 2 | 2.2 |
| s | 2.5 | 3 | 4 | 5 | 6 | 8 |
| t min | 1.3 | 2 | 2.5 | 3 | 4 | 5 |
| Teeth | 18 | 18 | 20 | 24 | 24 | 30 |
Bolts are packed in neutral packaging boxes, with standard quantities arranged in small cartons. The exact number of units per carton will be confirmed with the customer to align with their specific requirements. Customized packaging configurations are available upon request.
The small cartons are then consolidated into larger master cartons for secure transportation and storage. The quantity per master carton can be customized based on client specifications or aligned with standard logistical requirements.
The palletized units are securely wrapped with waterproof film and reinforced with packaging straps. Customer-specific shipping marks or labels are affixed to each pallet, ensuring clear identification and compliance with logistics requirements. This final packaging stage guarantees weather-resistant protection and stability during transportation.
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