M4 is one of the standard coarse-thread sizes for cap (acorn) nuts under DIN 1587. The sections below reproduce the dimensional row, list the matching tools and hole sizes, and summarize where this size is normally specified.
M4 Dimensional Row (DIN 1587)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e min (mm) | Total height m (mm) | Dome diameter (mm) | Reference standard | Notes |
|---|---|---|---|---|---|---|---|
| M4 | 0.7 | 7.0 | 7.66 | 8.0 | 7.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
Spanner & Drive for M4 Cap (Acorn) Nuts
Drive geometry for M4 Cap (Acorn) Nuts is given by the row above; match the tool to the listed values.
Common Applications for M4 Cap (Acorn) Nuts
M4 Cap (Acorn) Nuts are commonly specified for paired with the same-size screws on PCB hardware, light enclosures and small-scale assemblies.
Installation Tips for M4 Cap (Acorn) Nuts
- At M4 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
Mating Parts for M4
Pair M4 with the matching M4 bolt or screw, plus a M4 flat washer where required to distribute load on softer materials.