On the bench specifying M3 Flat Washers? This page gives the controlling dimensions for the M3 size of Flat Washers (to ISO 7089 / ISO 7093).
M3 Dimensional Row (ISO 7089 / ISO 7093)
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Thickness h (mm) | Reference standard |
|---|---|---|---|---|
| M3 | 3.2 | 7.0 | 0.5 | ISO 7089 |
Spanner & Drive for M3 Flat Washers
Drive geometry for M3 Flat Washers is given by the row above; match the tool to the listed values.
Common Applications for M3 Flat Washers
M3 Flat Washers are commonly specified for small electronics hardware and precision assemblies.
Installation Tips for M3 Flat 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.