Product Specifications
| Model / Specification | M3 - M10 |
| Material | Carbon steel |
| Thread d |
M3 | M3 | M4 | M4 | M5 | M5 | M6 | M6 | M8 | M8 | M10 | |
| D1 | Max. | 5.36 | 5.36 | 6.5 | 6.5 | 7.5 | 7.5 | 8.6 | 8.6 | 11.04 | 11.04 | 13.24 |
| Min. | 5.2 | 5.2 | 6.3 | 6.3 | 7.3 | 7.3 | 8.4 | 8.4 | 10.8 | 10.8 | 13 | |
| H | Nom. | 7.5 | 10.5 | 8 | 11.5 | 9.5 | 12.5 | 10 | 13.5 | 13 | 16 | 16 |
| Max. | 7.68 | 10.68 | 8.18 | 11.68 | 9.68 | 12.68 | 10.18 | 13.68 | 13.22 | 16.22 | 16.22 | |
| Min. | 7.32 | 10.32 | 7.82 | 11.32 | 9.32 | 12.32 | 9.82 | 13.32 | 12.78 | 15.78 | 15.78 | |
| L1 | Nom. | 12 | 12 | 16 | 16 | 16 | 16 | 18 | 18 | 22 | 22 | 26 |
| Max. | 12.2 | 12.2 | 16.2 | 16.2 | 16.2 | 16.2 | 18.2 | 18.2 | 22.2 | 22.2 | 26.2 | |
| Min. | 11.8 | 11.8 | 15.8 | 15.8 | 15.8 | 15.8 | 17.8 | 17.8 | 21.8 | 21.8 | 25.8 | |
| L | Ref. | 19 | 19 | 23 | 23 | 23 | 23 | 25 | 25 | 31 | 31 | 35 |
| D | 7 | 7 | 9 | 9 | 9 | 9 | 11 | 11 | 14 | 14 | 17 | |
| d1 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 3.1 | 3.1 | 3.1 | |
| d2 | Max. | 3.92 | 3.92 | 3.92 | 3.92 | 3.92 | 3.92 | 3.92 | 3.92 | 4.66 | 4.66 | 4.66 |
| Min. | 3.8 | 3.8 | 3.8 | 3.8 | 3.8 | 3.8 | 3.8 | 3.8 | 4.5 | 4.5 | 4.5 | |
| h | 1.8 | 1.8 | 1.9 | 1.9 | 2 | 2 | 2.1 | 2.1 | 2.5 | 2.5 | 2.8 | |
| Wt./1,000 pcs (kg) | 0.801 | 0.87 | 1.177 | 1.261 | 1.457 | 1.536 | 1.87 | 2.107 | 4.193 | 4.352 | 6.923 | |
Airtight Two-Lug Plate Self-Locking Nut — Product Introduction
The airtight two-lug plate self-locking nut is a specialized fastener that integrates two-lug fixing, self-locking anti-loosening, and airtight sealing functions. The product adopts a two-lug plate structure and can be fixed to thin plates, housings, or structural parts by riveting or welding. After installation, it provides a reliable threaded connection without the need for backside access. The nut is equipped with an internal self-locking mechanism, such as a crimped deformed locking section or a non-metallic locking ring, and also offers airtight performance to effectively prevent gas or liquid leakage along the threaded area. This product is usually manufactured from high-quality alloy steel, stainless steel, or high-temperature alloy. After heat treatment, it achieves high strength, hardness, and fatigue resistance. Common surface treatments include cadmium plating, zinc plating, passivation, and silver plating to meet corrosion resistance and lubrication requirements in different environments. The airtight two-lug plate self-locking nut is available in a wide range of metric and inch thread sizes and is widely used in aviation, aerospace, shipbuilding, hydraulic and pneumatic systems, and various threaded connection applications that require both sealing and anti-loosening performance.
1. Product Features
• Two-lug plate structure: With lugs on both sides, it can be fixed to thin plates or housings by riveting or welding, providing stable installation and suitability for single-side assembly.
• Airtight performance: Through a special sealing structure, sealing surface design, or use with a sealing ring, it effectively prevents gas or liquid leakage along the threads.
• Self-locking function: Self-locking methods such as crimped deformed sections or non-metallic locking rings ensure locking is maintained under vibration and impact conditions.
• High-quality materials: Commonly made from alloy steel, stainless steel, high-temperature alloy, and other materials, offering high strength and good fatigue resistance.
• Various surface treatments: Cadmium plating, zinc plating, passivation, silver plating, and other treatments are available to improve corrosion resistance and assembly performance.
• Complete specifications: Available in a variety of metric and inch thread sizes to match different bolts and installation environments.
2. Product Advantages
• Reliable sealing: The airtight design meets the connection requirements of hydraulic and pneumatic systems, as well as sealed cabins and enclosures.
• Strong anti-vibration and anti-loosening capability: The stable self-locking structure effectively prevents thread loosening even under continuous vibration and impact.
• Convenient single-side installation: The two-lug plate can be pre-fixed by riveting or welding, eliminating the need for backside access during assembly and improving efficiency.
• Good load-bearing performance: High-quality materials combined with heat treatment give the nut high axial load capacity and pull-out resistance.
• Good environmental adaptability: Different surface treatments allow it to withstand salt spray, humidity, corrosive media, and other environments.
• Easy maintenance and replacement: The standardized structure allows quick removal and replacement after damage, reducing maintenance costs.
3. Application Scope
• Aerospace: Areas requiring airtight and anti-loosening connections, such as aircraft skins, cabin equipment, structural frames, and fuel tanks.
• Shipbuilding: Threaded connections requiring sealing and anti-loosening in hull structures, cabin equipment, and piping accessories.
• Hydraulic and pneumatic systems: Parts with sealing requirements, such as hydraulic valve blocks, pneumatic components, and pipeline connections.
• Automotive industry: Connections requiring anti-loosening and airtightness, such as chassis, engine accessories, and body sealing areas.
• Electronic equipment: Thin-walled structures requiring sealing, such as enclosures, cabinets, and instrument housings.
• Rail transit and general industry: Threaded connection applications requiring single-side installation, sealing, and anti-loosening, such as interior fittings, electrical boxes, and similar components.
