M30 Studs & Threaded Rods (DIN 939 / DIN 975) are specified by thread size, length and head dimensions. The M30 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M30 Dimensional Row (DIN 939 / DIN 975)
| Thread size | Pitch (mm) | Point type | Common lengths (mm) | Reference standard | Notes |
|---|---|---|---|---|---|
| M30 | 3.5 | M30 | 60~300 | DIN 939 | Stud, equal thread both ends |
Hole Sizes for M30
| Coarse-thread pitch (ISO 724) | 3.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 33 mm |
| Tapping drill, coarse thread | 26.5 mm |
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 Studs & Threaded Rods
M30 Studs & Threaded Rods are commonly specified for structural steelwork, heavy machinery foundations and large flange joints.
Mating Parts for M30
For M30, pair with a M30 hex nut (ISO 4032 / DIN 934) and, where used, a M30 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.

