Flat Washers manufactured to ISO 7093 follow a specific scope. This page summarizes that scope, lists every dimension the standard fixes, and points to the most common cross-references.
ISO 7093 — Scope
ISO 7093 specifies the dimensions and tolerances of flat washers. 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
ISO 7093, alongside the related ISO 7089 / ISO 7093 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 ISO 7093
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Thickness h (mm) | Reference standard |
|---|---|---|---|---|
| M1.6 | 1.7 | 4.0 | 0.3 | ISO 7089 |
| M2 | 2.2 | 5.0 | 0.3 | ISO 7089 |
| M2.5 | 2.7 | 6.0 | 0.5 | ISO 7089 |
| M3 | 3.2 | 7.0 | 0.5 | ISO 7089 |
| M3.5 | 3.7 | 8.0 | 0.5 | ISO 7089 |
| M4 | 4.3 | 9.0 | 0.8 | ISO 7089 |
| M5 | 5.3 | 10.0 | 1.0 | ISO 7089 |
| M6 | 6.4 | 12.0 | 1.6 | ISO 7089 |
| M7 | 7.4 | 14.0 | 1.6 | ISO 7089 |
| M8 | 8.4 | 16.0 | 1.6 | ISO 7089 |
| M10 | 10.5 | 20.0 | 2.0 | ISO 7089 |
| M12 | 13.0 | 24.0 | 2.5 | ISO 7089 |
| M14 | 15.0 | 28.0 | 2.5 | ISO 7089 |
| M16 | 17.0 | 30.0 | 3.0 | ISO 7089 |
| M18 | 19.0 | 34.0 | 3.0 | ISO 7089 |
| M20 | 21.0 | 37.0 | 3.0 | ISO 7089 |
| M22 | 23.0 | 39.0 | 3.0 | ISO 7089 |
| M24 | 25.0 | 44.0 | 4.0 | ISO 7089 |
| M27 | 28.0 | 50.0 | 4.0 | ISO 7089 |
| M30 | 31.0 | 56.0 | 4.0 | ISO 7089 |
| M33 | 34.0 | 60.0 | 5.0 | ISO 7089 |
| M36 | 37.0 | 66.0 | 5.0 | ISO 7089 |
| M39 | 40.0 | 72.0 | 6.0 | ISO 7089 |
| M42 | 43.0 | 78.0 | 7.0 | ISO 7089 |
| M45 | 46.0 | 85.0 | 7.0 | ISO 7089 |
| M48 | 50.0 | 92.0 | 8.0 | ISO 7089 |
| M52 | 54.0 | 98.0 | 8.0 | ISO 7089 |
| M56 | 58.0 | 105.0 | 9.0 | ISO 7089 |
| M60 | 62.0 | 110.0 | 9.0 | ISO 7089 |
| M64 | 66.0 | 115.0 | 9.0 | ISO 7089 |
| M5 | 5.3 | 15.0 | 1.0 | ISO 7093 large series |
| M6 | 6.4 | 18.0 | 1.6 | ISO 7093 large series |
| M8 | 8.4 | 24.0 | 2.0 | ISO 7093 large series |
| M10 | 10.5 | 30.0 | 2.5 | ISO 7093 large series |
| M12 | 13.0 | 37.0 | 3.0 | ISO 7093 large series |
| M16 | 17.0 | 50.0 | 3.0 | ISO 7093 large series |
| M20 | 21.0 | 60.0 | 4.0 | ISO 7093 large series |
| M24 | 25.0 | 72.0 | 5.0 | ISO 7093 large series |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Flat Washers page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
ISO 7093 controls only the geometry of flat washers. 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).