DIN 9021 is the standard cited for fender washers. This page sets out what the standard controls for this part, reproduces the dimensional table supplied against it, and notes the related designations referenced on drawings.
DIN 9021 — Scope
DIN 9021 specifies the dimensional requirements for fender washers. Material, surface condition and any performance rating are set by separate documents specific to this part family — ISO 898-1 and ISO 898-2, which govern bolt and nut property classes, do not apply here.
Tolerance & Product Grades
Tolerances for fender washers are given as limits on the individual dimensions in the table rather than as a fastener product grade. Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by DIN 9021
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Thickness h (mm) | Reference standard | Notes |
|---|---|---|---|---|---|
| M3 | 3.2 | 9.0 | 0.8 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M4 | 4.3 | 12.0 | 1.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M5 | 5.3 | 15.0 | 1.2 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M6 | 6.4 | 18.0 | 1.6 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M8 | 8.4 | 24.0 | 2.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M10 | 10.5 | 30.0 | 2.5 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M12 | 13.0 | 37.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M14 | 15.0 | 44.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M16 | 17.0 | 50.0 | 3.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M20 | 21.0 | 60.0 | 4.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M24 | 25.0 | 72.0 | 5.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M30 | 31.0 | 90.0 | 6.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
| M36 | 37.0 | 110.0 | 8.0 | DIN 9021 / ISO 7093 | Oversized OD for bearing on soft materials |
Companion Standards
DIN 9021 controls only the geometry of fender washers. Surface finish is governed by separate finish standards (for example ISO 4042 for electroplating), and corrosion testing by ISO 9227 (neutral salt spray). Mechanical performance is set by the standards specific to this part family, not by ISO 898-1 or ISO 898-2, which apply to bolts, screws and nuts.
When to Specify DIN 9021
DIN 9021 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.
