M4 Square Nut, Metric are manufactured to GB/T 39 / ISO 4034 with a coarse thread pitch of 0.7 mm. This page lists the controlling dimensions for the M4 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M4 Dimensional Row (GB/T 39 / ISO 4034)
| Size | Pitch (mm) | Width across flats s (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|
| M4 | 0.7 | 7.0 | 2.2 | GB/T 39 / DIN 562 |
Spanner & Drive for M4 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076)
Drive geometry for M4 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076) is given by the row above; match the tool to the listed values.
Common Applications for M4 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076)
M4 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076) are commonly specified for paired with the same-size screws on PCB hardware, light enclosures and small-scale assemblies.
Mating Parts for M4
Pair M4 with the matching M4 bolt or screw, plus a M4 flat washer where required to distribute load on softer materials.
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.

