The M30 size of Hex Slotted Castle Nut (Type 2) is dimensioned by GB/T 6180 / ISO 7036. The table below gives the dimensional row from the standard, followed by the drive and the installation notes for this type.
M30 Dimensional Row (GB/T 6180 / ISO 7036)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Total height m (mm) | Slot width (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M30 | 3.5 | 46.0 | 50.85 | 36.0 | 7.0 | ISO 7036 / GB/T 6180 |
Spanner & Drive for M30 Hex Slotted Castle Nut (Type 2) — GB/T 6180 / ISO 7036 (Series 050)
Drive geometry for M30 Hex Slotted Castle Nut (Type 2) — GB/T 6180 / ISO 7036 (Series 050) is given by the row above; match the tool to the listed values.
Tightening Torque for M30
| Class 8.8 (dry, ~µ 0.125) | ≈ 1400 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 2000 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 2400 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 M30
| Tensile stress area As (ISO 898-1) | 561 mm² |
|---|---|
| Proof load, class 8.8 | 337 kN |
| Proof load, class 10.9 | 466 kN |
| Proof load, class 12.9 | 544 kN |
| Min. ultimate tensile, class 8.8 | 449 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 M30 Hex Slotted Castle Nut (Type 2) — GB/T 6180 / ISO 7036 (Series 050)
M30 Hex Slotted Castle Nut (Type 2) — GB/T 6180 / ISO 7036 (Series 050) are commonly specified for structural joints, flange connections and heavy equipment foundations.
Installation Tips for M30 Hex Slotted Castle Nut (Type 2) — GB/T 6180 / ISO 7036 (Series 050)
- At M30 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 M30
Pair M30 with the matching M30 bolt or screw, plus a M30 flat washer where required to distribute load on softer materials.

