For hex thick nut, DIN 6330 defines the dimensions, tolerances and product grades. 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 6330 — Scope
DIN 6330 specifies the dimensions and tolerances of hex thick nut — din 6330 / gb/t 56 (series 052). 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 / GB/T 56 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
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 0.5 | 5.5 | 6.01 | 2.4 | ISO 4032 / GB/T 6170 |
| M4 | 0.7 | 7.0 | 7.66 | 3.2 | ISO 4032 / GB/T 6170 |
| M5 | 0.8 | 8.0 | 8.79 | 4.7 | ISO 4032 / GB/T 6170 |
| M6 | 1.0 | 10.0 | 11.05 | 5.2 | ISO 4032 / GB/T 6170 |
| M8 | 1.25 | 13.0 | 14.38 | 6.8 | ISO 4032 / GB/T 6170 |
| M10 | 1.5 | 16.0 | 17.77 | 8.4 | ISO 4032 / GB/T 6170 |
| M12 | 1.75 | 18.0 | 20.03 | 10.8 | ISO 4032 / GB/T 6170 |
| M14 | 2.0 | 21.0 | 23.36 | 12.8 | ISO 4032 / GB/T 6170 |
| M16 | 2.0 | 24.0 | 26.75 | 14.8 | ISO 4032 / GB/T 6170 |
| M18 | 2.5 | 27.0 | 30.14 | 15.8 | ISO 4032 / GB/T 6170 |
| M20 | 2.5 | 30.0 | 33.53 | 18.0 | ISO 4032 / GB/T 6170 |
| M24 | 3.0 | 36.0 | 39.98 | 21.5 | ISO 4032 / GB/T 6170 |
| M30 | 3.5 | 46.0 | 50.85 | 25.6 | ISO 4032 / GB/T 6170 |
| M36 | 4.0 | 55.0 | 60.79 | 31.0 | ISO 4032 / GB/T 6170 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Hex Thick Nut — DIN 6330 / GB/T 56 (Series 052) 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.