For cap (acorn) nuts, DIN 1587 fixes the geometry and the tolerances. The sections below describe the scope of the document, the properties it deliberately leaves to companion standards, and the equivalent designations across standards bodies.
DIN 1587 — Scope
DIN 1587 is "Hexagon cap nuts (acorn nuts), high type".
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
DIN 1587 does not divide cap (acorn) nuts into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by 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 |
| M5 | 0.8 | 8.0 | 8.79 | 10.0 | 8.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M6 | 1.0 | 10.0 | 11.05 | 12.0 | 10.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M8 | 1.25 | 13.0 | 14.38 | 15.0 | 13.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M10 | 1.5 | 17.0 | 18.90 | 18.0 | 17.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M12 | 1.75 | 19.0 | 21.10 | 22.0 | 19.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M16 | 2.0 | 24.0 | 26.75 | 28.0 | 24.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
| M20 | 2.5 | 30.0 | 33.53 | 34.0 | 30.0 | DIN 1587 | Closed-end domed cap nut, decorative / protective |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Cap (Acorn) Nuts page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
DIN 1587 controls only the geometry of cap (acorn) nuts. The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
Custom manufacturing · Made to drawing
Need a nut to this standard in a non-standard size?
Parts built to DIN 1587 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
