This page covers M12 Cap (Acorn) Nuts to DIN 1587: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (DIN 1587 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M12 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 |
|---|---|---|---|---|---|---|---|
| M12 | 1.75 | 19.0 | 21.10 | 22.0 | 19.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
Spanner & Drive for M12 Cap (Acorn) Nuts
Drive geometry for M12 Cap (Acorn) Nuts is given by the row above; match the tool to the listed values.
Common Applications for M12 Cap (Acorn) Nuts
M12 Cap (Acorn) Nuts are commonly specified for medium-duty structural joints and motor / chassis mounting.
Mating Parts for M12
Pair M12 with the matching M12 bolt or screw, plus a M12 flat washer where required to distribute load on softer materials.
When to Step Up or Down from M12
When the joint preload approaches the proof load of M12 class 8.8, step up to M16 class 8.8 (or move to M12 class 10.9). When the joint is over-specified, M10 often saves weight and cost without losing the safety margin.