M10 Hex Flange Bolts is the m10-thread variant of Hex Flange Bolts manufactured to ISO 1665 / DIN 6921. This page focuses on the data engineers reach for at the bench: dimensional values for the M10 size, the spanner/drive that fits, and the assembly data you need to install it.
M10 Dimensional Row (ISO 1665 / DIN 6921)
| Size | Pitch (mm) | Flange diameter dc (mm) | Head height k (mm) | Width across flats s (mm) | Reference standard |
|---|---|---|---|---|---|
| M10 | 1.5 | 21.8 | 8.9 | 15.0 | ISO 1665 / DIN 6921 |
Spanner & Drive for M10 Hex Flange Bolts
M10 Hex Flange Bolts have a width across flats of 15.0 mm — fit a 15.0 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 M10
| Coarse-thread pitch (ISO 724) | 1.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 11 mm |
| Tapping drill, coarse thread | 8.5 mm |
Tightening Torque for M10
| Class 8.8 (dry, ~µ 0.125) | ≈ 49 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 69 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 83 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 M10 Hex Flange Bolts
- 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 M10
For M10, pair with a M10 hex nut (ISO 4032 / DIN 934) and, where used, a M10 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M10
When the joint preload approaches the proof load of M10 class 8.8, step up to M12 class 8.8 (or move to M10 class 10.9). When the joint is over-specified, M8 often saves weight and cost without losing the safety margin.