M2 Metric Thread
Direct Answer
M2 is an ISO metric machine screw thread with a nominal major diameter of 2.0 mm and a standard coarse pitch of 0.40 mm. Requiring a 1.60 mm tap drill, it is the universal standard thread for M.2 NVMe solid-state drive mounting standoffs and laptop internal chassis fastening.
Source: ISO 68-1 / ISO 261 / DIN 13-1 / PCI-SIG M.2 Specification
Specs
| Nominal Major Diameter | 2.00 mm |
| Standard Coarse Pitch | 0.40 mm |
| Fine Pitch (Optional) | 0.25 mm |
| Tap Drill Diameter | 1.60 mm (75% thread engagement) |
| Minor Diameter (Internal) | 1.567 mm |
| Tensile Stress Area | 2.07 mm² |
| Common Drive Size | PH0 / PH1 / T6 / T8 |
The M.2 SSD Standoff Standard
In PC and server hardware, the PCI-SIG M.2 specification standardizes M2 × 0.4 mm screws (typically 2.5 mm or 3.0 mm length with a wide wafer or pan head) to secure M.2 SSDs into motherboard standoff standoffs, making it one of the most frequently referenced fasteners in consumer computing.
Laptop Chassis and Electronics Assembly
M2 screws (typically paired with Torx T5/T6 or Phillips #00/0 heads) are used universally by Apple, Dell, Lenovo, and HP to secure internal motherboards, heatsinks, Wi-Fi cards, and exterior unibody laptop bottom covers.