DIN 6330 covers the dimensional requirements for hex thick nuts (din 6330). Reproduced below: the complete size table, the tolerance grades, and the companion and equivalent standards referenced when ordering to this document.
DIN 6330 — Scope
DIN 6330 specifies the dimensions and tolerances of hex thick nuts (din 6330). Material, property class, surface finish and packaging are governed by separate documents in the same standards family (for example ISO 898-1 for the mechanical property classes of bolts and screws).
Tolerance & Product Grades
DIN 6330, alongside the related DIN 6330 entries on this site, specifies product grades (typically A or B for fine work and C for general engineering) and tolerance classes for the controlling dimensions. Choose the grade against the precision your application requires.
Dimensions Specified by DIN 6330
| Thread size | Pitch (mm) | Width across flats s (mm) | Nut height m (mm) | Height ratio m/d | Engaged threads | Property class | Reference standard |
|---|---|---|---|---|---|---|---|
| M8 | 1.25 | 13.0 | 12.0 | 1.5 | approx. 9.6 | 10 | DIN 6330 |
| M10 | 1.5 | 17.0 | 15.0 | 1.5 | approx. 10.0 | 10 | DIN 6330 |
| M12 | 1.75 | 19.0 | 18.0 | 1.5 | approx. 10.3 | 10 | DIN 6330 |
| M16 | 2.0 | 24.0 | 24.0 | 1.5 | approx. 12.0 | 10 | DIN 6330 |
| M20 | 2.5 | 30.0 | 30.0 | 1.5 | approx. 12.0 | 10 | DIN 6330 |
| M24 | 3.0 | 36.0 | 36.0 | 1.5 | approx. 12.0 | 10 | DIN 6330 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Hex Thick Nuts (DIN 6330) page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify DIN 6330
DIN 6330 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.
