Hex Flange Cap Nut GB/T 802.3 - Carbon Steel Electro-Galvanized Fastener
Standard: GB/T 802.3
The hex flange cap nut (also known as hexagonal flange cap nut) is a high-performance fastener integrating the functions of a hex nut, a flange washer, and a protective cap. Designed for industrial assembly and mechanical fastening, it features a hexagonal head for easy torque application, an integrated flange face (with serrations in most cases), and a closed cap-style top—combining reliability, anti-loosening performance, and corrosion protection in one component.
- Hexagonal Head Design: The standard hexagonal shape enables compatibility with common tools (wrenches, sockets), ensuring efficient installation and disassembly even in confined spaces.
- Integrated Flange Face: The built-in flange (a circular washer-like structure) eliminates the need for additional washers, increasing the contact area with the workpiece. Serrated flanges enhance anti-loosening performance by preventing rotation under vibration, making it ideal for dynamic load scenarios.
- Closed Cap Style: The closed top seals the internal thread, protecting it from dust, moisture, debris, and corrosion—extending the fastener's service life and maintaining connection integrity in harsh environments.
Widely used in machinery manufacturing, automotive industry, electronic equipment, construction machinery, furniture assembly, and marine hardware. It is particularly suitable for scenarios requiring stable fastening, corrosion resistance, and thread protection—such as outdoor equipment, automotive components, and precision instruments.
| d | M5 | M6 | M8 | M10 | M12 | M16 | M20 | M24 |
|---|---|---|---|---|---|---|---|---|
| P (coarse thread) | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 |
| P (fine thread) | / | / | 1 | 1 | 1.5 | 1.5 | 2 | 2 |
| P (fine thread) | / | / | / | 1.25 | 1.25 | / | 1.5 | / |
| dk MAX | 7.5 | 9.5 | 12.5 | 15 | 17 | 23 | 28 | 34 |
| dc MAX | 11.8 | 14.2 | 17.9 | 21.8 | 26 | 34.5 | 42.8 | 46 |
| e MIN | 8.79 | 11.05 | 14.38 | 17.77 | 20.03 | 26.75 | 32.95 | 39.55 |
| h MAX | 9 | 11 | 14 | 18 | 22 | 30 | 32 | 36 |
| h MIN | 8.64 | 10.57 | 13.57 | 17.57 | 21.48 | 29.48 | 31 | 35 |
| m MAX | 5 | 6 | 8 | 10 | 12 | 16 | 20 | 24 |
| m MIN | 4.7 | 5.7 | 7.64 | 9.64 | 11.57 | 15.3 | 18.7 | 22.7 |
| SR ≈ | 3.75 | 4.75 | 6.25 | 7.5 | 8.5 | 11.5 | 14 | 17 |
| s MAX | 8 | 10 | 13 | 16 | 18 | 24 | 30 | 36 |
| s MIN | 7.78 | 9.78 | 12.73 | 15.73 | 17.73 | 23.67 | 29.16 | 35 |
| t ≈ | 0.5 | 0.8 | 0.8 | 0.8 | 1 | 1 | 1.2 | 1.2 |
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