M12 Hex Slotted Nut are manufactured to GB/T 6181 / ISO 4035 with a coarse thread pitch of 1.75 mm. This page lists the controlling dimensions for the M12 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M12 Dimensional Row (GB/T 6181 / ISO 4035)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M12 | 1.75 | 18.0 | 20.03 | 6.0 | ISO 4035 / GB/T 6172 |
Spanner & Drive for M12 Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054)
M12 Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054) have a width across flats of 18.0 mm — fit a 18.0 mm open-ended spanner or socket. Use a 6-point socket for tight clearances and to reduce rounding; for repeated assembly choose a torque wrench so the joint preload is repeatable.
Common Applications for M12 Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054)
M12 Hex Slotted Nut — GB/T 6181 / ISO 4035 (Series 054) 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.