For t-slot nuts, DIN 508 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 508 — Scope
DIN 508 specifies the dimensions and tolerances of t-slot nuts. 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 508, alongside the related DIN 508 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 508
| Thread size | T-slot width (mm) | Nut width b (mm) | Total height h (mm) | Key height h1 (mm) | Hook width e (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M5 | 6 | 8.0 | 8.0 | 4.5 | 6.4 | DIN 508 / GN505 |
| M6 | 8 | 10.0 | 10.0 | 5.5 | 8.4 | DIN 508 / GN505 |
| M8 | 10 | 12.0 | 12.0 | 7.0 | 10.4 | DIN 508 / GN505 |
| M8 | 12 | 14.0 | 12.0 | 7.0 | 12.4 | DIN 508 / GN505 |
| M10 | 12 | 14.0 | 14.0 | 8.0 | 12.4 | DIN 508 / GN505 |
| M10 | 14 | 16.0 | 14.0 | 8.0 | 14.4 | DIN 508 / GN505 |
| M12 | 14 | 16.0 | 17.0 | 10.0 | 14.4 | DIN 508 / GN505 |
| M12 | 18 | 20.0 | 17.0 | 10.0 | 18.4 | DIN 508 / GN505 |
| M16 | 18 | 20.0 | 20.0 | 12.0 | 18.4 | DIN 508 / GN505 |
| M16 | 22 | 25.0 | 20.0 | 12.0 | 22.4 | DIN 508 / GN505 |
| M20 | 22 | 25.0 | 25.0 | 15.0 | 22.4 | DIN 508 / GN505 |
| M20 | 28 | 32.0 | 25.0 | 15.0 | 28.4 | DIN 508 / GN505 |
| M24 | 28 | 32.0 | 30.0 | 18.0 | 28.4 | DIN 508 / GN505 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent T-Slot Nuts page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
DIN 508 controls only the geometry of t-slot nuts. The mechanical strength is set by ISO 898-1 (bolts and screws) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards (e.g. ISO 4042 for electroplating). For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).