The M8 size of Thin Hex Nut is dimensioned by GB/T 6172.1 / ISO 4035. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.
M8 Dimensional Row (GB/T 6172.1 / ISO 4035)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M8 | 1.25 | 13.0 | 14.38 | 4.0 | ISO 4035 / GB/T 6172 |
Spanner & Drive for M8 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055)
M8 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055) have a width across flats of 13.0 mm — fit a 13.0 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 M8 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055)
M8 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055) are commonly specified for general-purpose joints in machinery, fixturing and equipment frames.
Installation Tips for M8 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055)
- 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 M8
When the joint preload approaches the proof load of M8 class 8.8, step up to M10 class 8.8 (or move to M8 class 10.9). When the joint is over-specified, M6 often saves weight and cost without losing the safety margin.