This page covers M12 Square Nut, Metric to GB/T 39 / ISO 4034: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (GB/T 39 / ISO 4034 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M12 Dimensional Row (GB/T 39 / ISO 4034)
| Size | Pitch (mm) | Width across flats s (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|
| M12 | 1.75 | 19.0 | 7.0 | GB/T 39 / DIN 562 |
Spanner & Drive for M12 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076)
Drive geometry for M12 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 M12 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076)
M12 Square Nut, Metric — GB/T 39 / ISO 4034 (Series 076) are commonly specified for medium-duty structural joints and motor / chassis mounting.
Mating Parts for M12
Pair M12 with the matching M12 bolt or screw, plus a M12 flat washer where required to distribute load on softer materials.
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.