The M4 size of Spring Lock Washer is dimensioned by GB/T 5782 / ISO 4014. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.
M4 Dimensional Row (GB/T 5782 / ISO 4014)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Width b (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|---|
| M4 | 4.1 | 7.6 | 1.2 | 1.0 | GB/T 93 / DIN 127B |
Spanner & Drive for M4 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
Drive geometry for M4 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) is given by the row above; match the tool to the listed values.
Common Applications for M4 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
M4 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) are commonly specified for small electronics hardware and precision assemblies.
Installation Tips for M4 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
- 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.

