A cap (acorn) nut in M4: this guide pulls the row from the standard, adds the assembly numbers an engineer actually uses, and links you straight to a quote.
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.
When to Step Up or Down from M4
When the joint preload approaches the proof load of M4 class 8.8, step up to M5 class 8.8 (or move to M4 class 10.9). When the joint is over-specified, M3 often saves weight and cost without losing the safety margin.