Sub-M2 Precision Screws: Manufacturing at Watchmaking Tolerances
An M1 screw's head is 0.3 mm thick — thinner than a human hair is wide is almost true. Manufacturing at this scale is a different craft with different equipment.
How micro screws are made
Micro heading forms blanks from fine wire at speeds conventional machines cannot touch; the dies themselves are precision artifacts. Threads roll at sizes where a hair's-width error is a pitch. Every handling step — heat treatment, coating, packaging — risks tangles and damage, so vibratory and tape-based handling replaces human hands early.
Tolerances that matter at M1
- Head height ±0.03 mm and slot/hex depth dominate drive reliability — a shallow hex strips in torque.
- Concentricity between head and shank decides whether the screw seats without wobble in optical assemblies.
- Coating thickness must shrink with the part: 5 µm plating on M1 changes thread fit by a visible margin.
Where they serve
Watches, camera modules, hearing aids, micro drones and surgical instruments. Topprecision manufactures sub-M2 precision screws with 100% optical inspection, PVD and ultra-thin coating options, and tape packaging compatible with automated micro-assembly cells.
