M12 Plain Washer — GB/T 858 (Series 071) is the m12-thread variant of Plain Washer — GB/T 858 (Series 071) manufactured to GB/T 858. This page focuses on the data engineers reach for at the bench: dimensional values for the M12 size, the spanner/drive that fits, and the assembly data you need to install it.
M12 Dimensional Row (GB/T 858)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| M12 | 13.0 | 24.0 | 2.5 | ISO 7089 / GB/T 97.1 |
Spanner & Drive for M12 Plain Washer — GB/T 858 (Series 071)
Drive geometry for M12 Plain Washer — GB/T 858 (Series 071) is given by the row above; match the tool to the listed values.
Common Applications for M12 Plain Washer — GB/T 858 (Series 071)
M12 Plain Washer — GB/T 858 (Series 071) are commonly specified for medium-duty structural joints.
Mating Parts for M12
A M12 flat washer pairs with a M12 bolt/screw and matching M12 nut.
When to Step Up or Down from M12
When the joint preload approaches the proof load of M12 class 8.8, step up to M16 class 8.8 (or move to M12 class 10.9). When the joint is over-specified, M10 often saves weight and cost without losing the safety margin.