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M8 nut size
13 mm wrench
wrench size for M8 hex nut
M8 hex nut — standard metric hexagonal nut.
Full specification
| System | Metric |
| Nominal diameter | 8 mm |
| Wrench size (across flats) | 13 mm |
| Nut thickness | 6.5 mm |
| Common grade / class | Class 8 |
About M8 nuts
M8 hex nuts are standard metric hexagonal nuts used with M8 bolts and threaded rods.
The wrench size 13 mm is measured across the flats of the hexagon. The nut thickness is 6.5 mm.
Class 8 indicates the strength rating. These nuts are suitable for general-purpose applications.
Frequently asked questions
- What size wrench fits M8 nut?
- M8 nut uses a 13 mm wrench.
- How thick is a M8 nut?
- A standard M8 hex nut is 6.5 mm thick.
- What is the difference between M8 nut classes?
- Class Class 8 indicates the strength rating. Higher numbers mean stronger nuts.