Dimensional data for M5 Hex Flange Nuts to ISO 4161 / DIN 6923, with the drive and the installation notes for this type. Values are taken from the governing standard rather than from a general machine-thread table, because this type is not selected on one.
M5 Dimensional Row (ISO 4161 / DIN 6923)
| Size | Pitch (mm) | Flange diameter dc (mm) | Nut height m (mm) | Width across flats s (mm) | Reference standard |
|---|---|---|---|---|---|
| M5 | 0.8 | 11.8 | 5.0 | 8.0 | ISO 4161 / DIN 6923 |
Spanner & Drive for M5 Hex Flange Nuts
M5 Hex Flange Nuts have a width across flats of 8.0 mm — fit a 8.0 mm open-ended spanner or socket. Use a 6-point socket for tight clearances and to reduce rounding; for repeated assembly choose a torque wrench so the joint preload is repeatable.
Tightening Torque for M5
| Class 8.8 (dry, ~µ 0.125) | ≈ 5.8 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 8.1 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 9.7 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 M5
| Tensile stress area As (ISO 898-1) | 14.2 mm² |
|---|---|
| Proof load, class 8.8 | 8.2 kN |
| Proof load, class 10.9 | 11.8 kN |
| Proof load, class 12.9 | 13.8 kN |
| Min. ultimate tensile, class 8.8 | 11.4 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 M5 Hex Flange Nuts
M5 Hex Flange Nuts are commonly specified for paired with the same-size screws on PCB hardware, light enclosures and small-scale assemblies.
Installation Tips for M5 Hex Flange Nuts
- Use a 6-point socket where access allows — 12-point sockets are more prone to rounding the corners on smaller sizes.
- On flanged or serrated variants, do NOT add a separate flat washer — the flange already spreads the load and the washer can defeat the locking serrations.
- At M5 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 M5
Pair M5 with the matching M5 bolt or screw, plus a M5 flat washer where required to distribute load on softer materials.
