Dimensional and assembly data for M16 Hex Nut to GB/T 6170 / ISO 4032. Includes head size and width across flats, clearance-hole and tapping-drill diameters, tightening torque per property class, and the sizes to step up or down to when the joint requires it.
M16 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 |
|---|---|---|---|---|---|
| M16 | 2.0 | 24.0 | 26.75 | 14.8 | ISO 4032 / GB/T 6170 |
Spanner & Drive for M16 Hex Nut — GB/T 6170 / ISO 4032 (Series 061)
M16 Hex Nut — GB/T 6170 / ISO 4032 (Series 061) have a width across flats of 24.0 mm — fit a 24.0 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 M16 Hex Nut — GB/T 6170 / ISO 4032 (Series 061)
M16 Hex Nut — GB/T 6170 / ISO 4032 (Series 061) are commonly specified for medium-duty structural joints and motor / chassis mounting.
Installation Tips for M16 Hex Nut — GB/T 6170 / ISO 4032 (Series 061)
- 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.
When to Step Up or Down from M16
When the joint preload approaches the proof load of M16 class 8.8, step up to M20 class 8.8 (or move to M16 class 10.9). When the joint is over-specified, M12 often saves weight and cost without losing the safety margin.