M8 General Flat Washer are manufactured to GB/T 5782 / ISO 4014 with a coarse thread pitch of 1.25 mm. This page lists the controlling dimensions for the M8 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M8 Dimensional Row (GB/T 5782 / ISO 4014)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| M8 | 8.4 | 16.0 | 1.6 | ISO 7089 / GB/T 97.1 |
Spanner & Drive for M8 General Flat Washer — GB/T 5782 / ISO 4014 (Series 008)
Drive geometry for M8 General Flat Washer — GB/T 5782 / ISO 4014 (Series 008) is given by the row above; match the tool to the listed values.
Common Applications for M8 General Flat Washer — GB/T 5782 / ISO 4014 (Series 008)
M8 General Flat Washer — GB/T 5782 / ISO 4014 (Series 008) are commonly specified for general-purpose load-spreading and locking under machine bolts.
Mating Parts for M8
A M8 flat washer pairs with a M8 bolt/screw and matching M8 nut.
When to Step Up or Down from M8
When the joint preload approaches the proof load of M8 class 8.8, step up to M10 class 8.8 (or move to M8 class 10.9). When the joint is over-specified, M6 often saves weight and cost without losing the safety margin.