The M4 size of Hex Slotted Castle Nut (Type 1) is dimensioned by GB/T 6180 / ISO 7036. The table below gives the dimensional row from the standard, followed by the drive and the installation notes for this type.
M4 Dimensional Row (GB/T 6180 / ISO 7036)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Total height m (mm) | Slot width (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M4 | 0.7 | 7.0 | 7.66 | 5.0 | 1.5 | ISO 7036 / GB/T 6180 |
Spanner & Drive for M4 Hex Slotted Castle Nut (Type 1) — GB/T 6180 / ISO 7036 (Series 049)
Drive geometry for M4 Hex Slotted Castle Nut (Type 1) — GB/T 6180 / ISO 7036 (Series 049) 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 Hex Slotted Castle Nut (Type 1) — GB/T 6180 / ISO 7036 (Series 049)
M4 Hex Slotted Castle Nut (Type 1) — GB/T 6180 / ISO 7036 (Series 049) are commonly specified for paired with the same-size screws on PCB hardware, light enclosures and small-scale assemblies.
Installation Tips for M4 Hex Slotted Castle Nut (Type 1) — GB/T 6180 / ISO 7036 (Series 049)
- 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.
