M4 Studs & Threaded Rods are manufactured to DIN 939 / DIN 975 with a coarse thread pitch of 0.7 mm. This page lists the controlling dimensions for the M4 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M4 Dimensional Row (DIN 939 / DIN 975)
| Thread size | Pitch (mm) | Point type | Common lengths (mm) | Reference standard | Notes |
|---|---|---|---|---|---|
| M4 | 0.7 | M4 | 10~100 | DIN 939 | Stud, equal thread both ends |
Spanner & Drive for M4 Studs & Threaded Rods
Drive geometry for M4 Studs & Threaded Rods is given by the row above; match the tool to the listed values.
Hole Sizes for M4
| Coarse-thread pitch (ISO 724) | 0.7 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 4.5 mm |
| Tapping drill, coarse thread | 3.3 mm |
Tightening Torque for M4
| Class 8.8 (dry, ~µ 0.125) | ≈ 2.9 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 4.1 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 4.9 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 M4
| Tensile stress area As (ISO 898-1) | 8.78 mm² |
|---|---|
| Proof load, class 8.8 | 5.1 kN |
| Proof load, class 10.9 | 7.3 kN |
| Proof load, class 12.9 | 8.5 kN |
| Min. ultimate tensile, class 8.8 | 7 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.
M4 Studs & Threaded Rods Weight
A steel M4 studs & threaded rods at the listed 10,100 mm length weighs approximately 996 g each — about 996 kg per 1,000 pieces. Stainless A2/A4 weighs roughly the same (density 7.9–8.0 g/cm³). Actual weight varies slightly with head form, thread and finish; use this figure for freight estimation only.
Common Applications for M4 Studs & Threaded Rods
M4 Studs & Threaded Rods are commonly specified for precision instruments, small machinery and consumer-electronics enclosures.
Mating Parts for M4
For M4, pair with a M4 hex nut (ISO 4032 / DIN 934) and, where used, a M4 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M4
When the joint preload approaches the proof load of M4 class 8.8, step up to M5 class 8.8 (or move to M4 class 10.9). When the joint is over-specified, M3 often saves weight and cost without losing the safety margin.