When you need Hex Flange Nuts in the M12 size, the controlling values come from ISO 4161 / DIN 6923. This page lists them in one place — pitch, head geometry, tool size and the matching hole.
M12 Dimensional Row (ISO 4161 / DIN 6923)
| Size | Pitch (mm) | Flange diameter dc (mm) | Nut height m (mm) | Width across flats s (mm) | Reference standard |
|---|---|---|---|---|---|
| M12 | 1.75 | 26.0 | 12.0 | 18.0 | ISO 4161 / DIN 6923 |
Spanner & Drive for M12 Hex Flange Nuts
M12 Hex Flange Nuts 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 Flange Nuts
M12 Hex Flange Nuts are commonly specified for medium-duty structural joints and motor / chassis mounting.
Installation Tips for M12 Hex Flange Nuts
- Use a 6-point socket where access allows — 12-point sockets are more prone to rounding the corners on smaller sizes.
- On flanged or serrated variants, do NOT add a separate flat washer — the flange already spreads the load and the washer can defeat the locking serrations.
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.