M4 All-Metal Prevailing Torque Hex Lock Nut (Type 1) are manufactured to GB/T 6184 / ISO 7042. This page lists the controlling dimensions for the M4 size together with the drive and the installation notes for this type.
M4 Dimensional Row (GB/T 6184 / ISO 7042)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Total height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M4 | 0.7 | 7.0 | 7.66 | 5.0 | ISO 7040 / DIN 985 |
Spanner & Drive for M4 All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047)
Drive geometry for M4 All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) is given by the row above; match the tool to the listed values.
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 All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047)
M4 All-Metal Prevailing Torque Hex Lock Nut (Type 1) — GB/T 6184 / ISO 7042 (Series 047) are commonly specified for paired with the same-size screws on PCB hardware, light enclosures and small-scale assemblies.
Mating Parts for M4
Pair M4 with the matching M4 bolt or screw, plus a M4 flat washer where required to distribute load on softer materials.
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.
