M6 Socket Nuts (Hex Drive, Round Body) are manufactured to Trade series (round body socket nut). This page lists the controlling dimensions for the M6 size together 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.
M6 Dimensional Row (Trade series (round body socket nut))
| Thread size | Outer diameter (mm) | Nut height m (mm) | Hex socket s (mm) | Socket depth (mm) | Material | Finish | Note |
|---|---|---|---|---|---|---|---|
| M6 | 12.0 | 12.0 | 6.0 | 5.5 | Alloy steel | Black oxide | Fits 12 mm bore |
Spanner & Drive for M6 Socket Nuts (Hex Drive, Round Body)
The hex socket for M6 Socket Nuts (Hex Drive, Round Body) is shown in the spec table — use the matching Allen / hex key (an ISO 2936 hex key set covers the full range). Ball-end keys are for reaching the screw, not for tightening it — finish on the plain end, and on production work use a torque-controlled driver.
Tightening Torque for M6
| Class 8.8 (dry, ~µ 0.125) | ≈ 10 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 14 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 17 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 M6
| Tensile stress area As (ISO 898-1) | 20.1 mm² |
|---|---|
| Proof load, class 8.8 | 12 kN |
| Proof load, class 10.9 | 17 kN |
| Proof load, class 12.9 | 19 kN |
| Min. ultimate tensile, class 8.8 | 16 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.
Mating Parts for M6
Pair M6 with the matching M6 bolt or screw, plus a M6 flat washer where required to distribute load on softer materials.
When to Step Up or Down from M6
When the joint preload approaches the proof load of M6 class 8.8, step up to M8 class 8.8 (or move to M6 class 10.9). When the joint is over-specified, M5 often saves weight and cost without losing the safety margin.
