M1.6 Metric Thread
Direct Answer
M1.6 is a miniature ISO metric machine screw thread with a nominal major diameter of 1.6 mm and a standard coarse pitch of 0.35 mm. Requiring a 1.25 mm tap drill, it is the standard fastening thread for precision optical equipment, wristwatches, and micro-electronic assemblies.
Source: ISO 68-1 / ISO 261 / DIN 13-1
Specs
| Nominal Major Diameter | 1.60 mm |
| Standard Coarse Pitch | 0.35 mm |
| Fine Pitch (Optional) | 0.20 mm |
| Tap Drill Diameter | 1.25 mm (75% thread engagement) |
| Minor Diameter (Internal) | 1.221 mm |
| Tensile Stress Area | 1.27 mm² |
| Thread Profile Angle | 60 degrees |
Miniature Precision Engineering
M1.6 threads are common in high-density electronic hardware, camera lens barrel assemblies, and precision medical sensors. Because of its microscopic 0.35 mm pitch, manual tapping requires specialized high-speed spiral flute taps and strict alignment to prevent tool breakage.
Standard Mechanical Applications
Widely used in sub-miniature PCB mounting brackets, eyeglass hinges, and micro-servo gearboxes in robotics where fastener weight and clearance must be strictly minimized.