M6 Hex Nut (GB/T 6170 / ISO 4032) are specified by thread size, length and head dimensions. The M6 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M6 Dimensional Row (GB/T 6170 / ISO 4032)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M6 | 1.0 | 10.0 | 11.05 | 5.2 | ISO 4032 / GB/T 6170 |
Spanner & Drive for M6 Hex Nut — GB/T 6170 / ISO 4032 (Series 066)
M6 Hex Nut — GB/T 6170 / ISO 4032 (Series 066) have a width across flats of 10.0 mm — fit a 10.0 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.
Common Applications for M6 Hex Nut — GB/T 6170 / ISO 4032 (Series 066)
M6 Hex Nut — GB/T 6170 / ISO 4032 (Series 066) are commonly specified for general-purpose joints in machinery, fixturing and equipment frames.
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.

