Product Specifications
| Model / Specification | M2-M10 |
| Material | Carbon steel, Stainless steel |
| Thread size d | M2 | M2.5 | M3 | (M3.5) | M4 | M5 | M6 | M8 | M10 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| P | Pitch |
0.4 | 0.45 | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 | 1.5 | |
| a | Max. |
0.8 | 0.9 | 1 | 1.2 | 1.4 | 1.6 | 2 | 2.5 | 3 | |
| dk ① | Theoretical | Max. | 4.4 | 5.5 | 6.3 | 8.2 | 9.4 | 10.4 | 12.6 | 17.3 | 20 |
| Actual | Max.=nominal | 3.8 | 4.7 | 5.5 | 7.3 | 8.4 | 9.3 | 11.3 | 15.8 | 18.3 | |
| Min. | 3.5 | 4.4 | 5.2 | 6.94 | 8.04 | 8.94 | 10.87 | 15.37 | 17.78 | ||
| f | ≈ |
0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.2 | 1.4 | 2 | 2.3 | |
| k ① | Max.=nominal |
1.2 | 1.5 | 1.65 | 2.35 | 2.7 | 2.7 | 3.3 | 4.65 | 5 | |
| r | Max. |
0.5 | 0.6 | 0.8 | 0.9 | 1.0 | 1.3 | 1.5 | 2.0 | 2.5 | |
| R | ≈ |
4 | 5 | 6 | 8.5 | 9.5 | 9.5 | 12 | 16.5 | 19.5 | |
| x | Max. |
1 | 1.1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3.2 | 3.8 | |
| Socket | Socket |
6 | 8 | 10 | 15 | 20 | 25 | 30 | 45 | 50 | |
| A | Ref. |
1.75 | 2.4 | 2.8 | 3.35 | 3.95 | 4.5 | 5.6 | 7.95 | 8.95 | |
| t | Max. |
0.77 | 1.04 | 1.15 | 1.53 | 1.8 | 2.03 | 2.42 | 3.31 | 3.81 | |
| Min. |
0.63 | 0.91 | 0.88 | 1.27 | 1.42 | 1.65 | 2.02 | 2.92 | 3.42 | ||
| Weight ≈ kg / 1000 pcs |
- | - | - | - | - | - | - | - | - | ||
| Thread length b | Min. |
- | - | - | - | - | - | - | - | - | |
Dimensions in mm. Data compiled from GB/T 2674-2017 for selection reference only; actual supply is subject to drawings and inspection reports.
Product Overview
The hexalobular socket semi-countersunk head screw, also known as a Torx semi-countersunk screw, is manufactured to GB/T 2674-2017. Its semi-countersunk head combines a shallow cone with a rounded top, so after tightening the head remains slightly above the workpiece surface, giving a neat rounded appearance while still providing the locating action of a countersink. The drive is a hexalobular (six-lobe / Torx) socket with rounded load flanks that spread the tightening torque evenly, reduce cam-out and suit automated assembly lines.
1. Product Features
- Semi-countersunk head (shallow cone with rounded top): sits slightly above the surface after assembly for a neat, rounded appearance.
- Combines the locating action of a countersunk head with the bearing area of a pan head; suits medium countersink depths.
- Hexalobular (Torx) socket drive: six rounded lobes transmit torque evenly, resist cam-out and protect the recess.
- Thread sizes from M2 to M10, covering a wide range of applications.
- Available in carbon steel and stainless steel, selected according to environment and strength requirements.
2. Product Advantages
- Compared with an ordinary countersunk head, the semi-countersunk head is thicker, giving better tensile strength and load-bearing capacity.
- The hexalobular recess together with a dedicated Torx driver allows higher tightening torque and reduces stripping and rejects during assembly.
- High degree of standardisation: the GB/T 2674 dimensional system is complete, which simplifies export matching and second sourcing.
- Material and surface finish can be customised to balance strength, corrosion resistance and cost.
3. Application Scope
- Electrical appliance and instrument housings that need countersink location but a rounded exterior.
- Assembly of furniture, hardware products and general machinery structural parts.
- Stainless steel versions suit damp or mildly corrosive environments, as well as food and medical equipment.
- Automated assembly lines and robotic tightening stations that require high recess fit accuracy.
