M24 Hex Nuts, Grade C are manufactured to ISO 4034 with a coarse thread pitch of 3 mm. This page lists the controlling dimensions for the M24 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M24 Dimensional Row (ISO 4034)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e min (mm) | Nut height m (mm) | Product grade | Reference standard |
|---|---|---|---|---|---|---|
| M24 | 3.0 | 36.0 | 39.55 | 21.5 | Grade C | ISO 4034 / DIN 555 |
Spanner & Drive for M24 Hex Nuts, Grade C
M24 Hex Nuts, Grade C have a width across flats of 36.0 mm — fit a 36.0 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 M24 Hex Nuts, Grade C
M24 Hex Nuts, Grade C are commonly specified for structural joints, flange connections and heavy equipment foundations.
Installation Tips for M24 Hex Nuts, Grade C
- 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.
- At M24 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.
Mating Parts for M24
Pair M24 with the matching M24 bolt or screw, plus a M24 flat washer where required to distribute load on softer materials.

