Dimensional data for M24 Hex Nut, Fine Pitch to GB/T 6171 / ISO 8673, with the drive and the installation notes for this type. Values are taken from the governing standard rather than from a general machine-thread table, because this type is not selected on one.
M24 Dimensional Row (GB/T 6171 / ISO 8673)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M24 | 3.0 | 36.0 | 39.98 | 21.5 | ISO 4032 / GB/T 6170 |
Spanner & Drive for M24 Hex Nut, Fine Pitch — GB/T 6171 / ISO 8673 (Series 067)
M24 Hex Nut, Fine Pitch — GB/T 6171 / ISO 8673 (Series 067) 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.
Tightening Torque for M24
| Class 8.8 (dry, ~µ 0.125) | ≈ 710 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 1000 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 1200 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M24
| Tensile stress area As (ISO 898-1) | 353 mm² |
|---|---|
| Proof load, class 8.8 | 212 kN |
| Proof load, class 10.9 | 293 kN |
| Proof load, class 12.9 | 342 kN |
| Min. ultimate tensile, class 8.8 | 282 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
Common Applications for M24 Hex Nut, Fine Pitch — GB/T 6171 / ISO 8673 (Series 067)
M24 Hex Nut, Fine Pitch — GB/T 6171 / ISO 8673 (Series 067) are commonly specified for structural joints, flange connections and heavy equipment foundations.
Installation Tips for M24 Hex Nut, Fine Pitch — GB/T 6171 / ISO 8673 (Series 067)
- 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.
