For Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032), the M4 thread sits in the small-to-medium range of the catalog and is one of the most-asked phillips pan head self-tapping screw — gb/t 845 / iso 7049 (series 032) in this family. The dimensional and assembly data follow.
M4 Dimensional Row (GB/T 845 / ISO 7049)
| Size | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Reference standard |
|---|---|---|---|---|---|---|
| M4 | 0.7 | 25 | 8.0 | 2.4 | PH2 | ISO 7045 / GB/T 818 |
Spanner & Drive for M4 Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032)
M4 Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032) 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.
Common Applications for M4 Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032)
M4 Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032) are commonly specified for electronics, PCB hardware, optical mounts and small-scale machinery.
Installation Tips for M4 Phillips Pan Head Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 032)
- Pozidriv (PZ) drivers ride out of Phillips (PH) recesses and vice versa — confirm the recess marking on the head before assembly.
- For automated assembly, an ACR (Anti-Cam-Out Ribs) or torx-equivalent driver gives noticeably longer bit life than plain PH.
- At M4 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
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.