M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) is the m4-thread variant of Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) manufactured to GB/T 95 / ISO 7091. This page focuses on the data engineers reach for at the bench: dimensional values for the M4 size, the spanner/drive that fits, and the assembly data you need to install it.
M4 Dimensional Row (GB/T 95 / ISO 7091)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| M4 | 4.3 | 9.0 | 0.8 | ISO 7089 / GB/T 97.1 |
Spanner & Drive for M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079)
Drive geometry for M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) is given by the row above; match the tool to the listed values.
Common Applications for M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079)
M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079) are commonly specified for small electronics hardware and precision assemblies.
Installation Tips for M4 Flat Plain Washer — GB/T 95 / ISO 7091 (Series 079)
- At M4 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 M4
A M4 flat washer pairs with a M4 bolt/screw and matching M4 nut.
When to Step Up or Down from M4
When the joint preload approaches the proof load of M4 class 8.8, step up to M5 class 8.8 (or move to M4 class 10.9). When the joint is over-specified, M3 often saves weight and cost without losing the safety margin.