A phillips pan head machine screw — gb/t 818 / iso 7045 (series 034 in M4: this guide pulls the row from the standard, adds the assembly numbers an engineer actually uses, and links you straight to a quote.
M4 Dimensional Row (GB/T 818 / ISO 7045)
| 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 Machine Screw — GB/T 818 / ISO 7045 (Series 034)
M4 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) 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 Machine Screw — GB/T 818 / ISO 7045 (Series 034)
M4 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034) are commonly specified for electronics, PCB hardware, optical mounts and small-scale machinery.
Installation Tips for M4 Phillips Pan Head Machine Screw — GB/T 818 / ISO 7045 (Series 034)
- 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.
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.