On the bench specifying M3 Fender Washers? This page gives the controlling dimensions for the M3 size of Fender Washers (to DIN 9021).
M3 Dimensional Row (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 |
Spanner & Drive for M3 Fender Washers
Drive geometry for M3 Fender Washers is given by the row above; match the tool to the listed values.
Common Applications for M3 Fender Washers
M3 Fender Washers are commonly specified for small electronics hardware and precision assemblies.
Installation Tips for M3 Fender Washers
- At M3 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
Mating Parts for M3
A M3 flat washer pairs with a M3 bolt/screw and matching M3 nut.
When to Step Up or Down from M3
When the joint preload approaches the proof load of M3 class 8.8, step up to M4 class 8.8 (or move to M3 class 10.9). When the joint is over-specified, M2 often saves weight and cost without losing the safety margin.