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 | Max.=nominal | 3.8 | 4.5 | 5.5 | 6 | 7 | 8.5 | 10 | 13 | 16 |
| Min. | 3.62 | 4.32 | 5.32 | 5.82 | 6.78 | 8.28 | 9.78 | 12.73 | 15.73 | |
| da | Max. | 2.6 | 3.1 | 3.6 | 4.1 | 4.7 | 5.7 | 6.8 | 9.2 | 11.2 |
| k | Max.=nominal | 1.55 | 1.85 | 2.4 | 2.6 | 3.1 | 3.65 | 4.4 | 5.8 | 6.9 |
| Min. | 1.41 | 1.71 | 2.26 | 2.46 | 2.92 | 3.47 | 4.1 | 5.5 | 6.54 | |
| r | Min. | 0.10 | 0.10 | 0.10 | 0.10 | 0.20 | 0.20 | 0.25 | 0.40 | 0.40 |
| w | Min. | 0.5 | 0.7 | 0.75 | 1.0 | 1.1 | 1.3 | 1.6 | 2.0 | 2.4 |
| x | Max. | 1.00 | 1.10 | 1.25 | 1.50 | 1.75 | 2.00 | 2.50 | 3.20 | 3.80 |
| Socket | T6 | T8 | T10 | T15 | T20 | T25 | T30 | T45 | T50 | |
| A | Ref. | 1.75 | 2.4 | 2.8 | 3.35 | 3.95 | 4.5 | 5.6 | 7.95 | 8.95 |
| t | Max. | 0.84 | 0.91 | 1.27 | 1.33 | 1.66 | 1.91 | 2.29 | 3.05 | 3.43 |
| Min. | 0.71 | 0.78 | 1.01 | 1.07 | 1.27 | 1.52 | 1.9 | 2.66 | 3.04 | |
| Weight ≈ kg / 1000 pcs | - | - | - | - | - | - | - | - | - | |
| Thread length b | Min. | - | - | - | - | - | - | - | - | - |
Dimensions in mm. The bracketed size (M3.5) is a non-preferred size. Data compiled from GB/T 2671.1-2017 for selection reference only; actual supply is subject to drawings and inspection reports.
Product Overview
The hexalobular socket low head cap screw, also known as a Torx low head cap screw or cheese head screw, is manufactured to GB/T 2671.1-2017, which corresponds to the international standard ISO 14580. Its head height is lower than that of a standard hex socket head cap screw, making it the better choice where installation space is limited. The drive is a hexalobular (six-lobe / Torx) socket with rounded load flanks that spread the tightening torque evenly, reducing the risk of cam-out and making the screw well suited to automated assembly lines.
1. Product Features
- Low head design with reduced head height, suitable for shallow counterbores and tight assembly spaces.
- Hexalobular (Torx) socket drive: six rounded lobes transmit torque evenly, resist cam-out and protect the recess.
- Thread sizes from M2 to M10, fully threaded, covering a wide range of applications.
- Wide choice of materials and grades: carbon steel 4.8 / 8.8 / 10.9, alloy steel SCM435 and stainless steel 304.
- Multiple surface finishes available: environmental zinc plating, black oxide, Dacromet, Geomet, bright finish and others, to match different corrosion requirements.
2. Product Advantages
- Compared with a cross recess or a plain hex socket, the hexalobular recess together with a dedicated Torx driver allows higher tightening torque and reduces stripping and rejects during assembly.
- The low head saves assembly height in thin plates, counterbores and space-restricted structures.
- High degree of standardisation: GB/T 2671.1 and ISO 14580 share the same dimensional system, which simplifies export matching and second sourcing.
- Material and surface finish can be customised to balance strength, corrosion resistance and cost.
3. Application Scope
- Assembly of small structural parts in precision instruments, electronics and office equipment.
- Fastening of automotive parts, motorcycles and general machinery (when 8.8 / 10.9 grades are selected).
- Stainless steel 304 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.
