M4 Pan Head Screws (ISO 1207 / ISO 7045 / DIN 7985) are specified by thread size, length and head dimensions. The M4 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M4 Dimensional Row (ISO 1207 / ISO 7045 / DIN 7985)
| Size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Reference standard |
|---|---|---|---|---|---|
| M4 | 0.7 | 8.0 | 2.4 | PH2 | ISO 1207 / ISO 7045 / DIN 7985 |
Spanner & Drive for M4 Pan Head Screws
M4 Pan Head Screws use a PH2 cross recess. Match the driver bit to the recess (Phillips PH / Pozi PZ are NOT interchangeable).
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.
Common Applications for M4 Pan Head Screws
M4 Pan Head Screws are commonly specified for electronics, PCB hardware, optical mounts and small-scale machinery.
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.