M6 Hex Bolts, Grade C is the m6-thread variant of Hex Bolts, Grade C manufactured to ISO 4016. This page focuses on the data engineers reach for at the bench: dimensional values for the M6 size, the spanner/drive that fits, and the assembly data you need to install it.
M6 Dimensional Row (ISO 4016)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e min (mm) | Head height k (mm) | Product grade | Reference standard |
|---|---|---|---|---|---|---|
| M6 | 1.0 | 10.0 | 10.89 | 4.15 | Grade C | ISO 4016 / DIN 601 |
Spanner & Drive for M6 Hex Bolts, Grade C
M6 Hex Bolts, Grade C 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.
Hole Sizes for M6
| Coarse-thread pitch (ISO 724) | 1 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 6.6 mm |
| Tapping drill, coarse thread | 5 mm |
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.
Installation Tips for M6 Hex Bolts, Grade C
- 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.
Mating Parts for M6
For M6, pair with a M6 hex nut (ISO 4032 / DIN 934) and, where used, a M6 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
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.