Metric Nut Sizes

Nut Size Diameter* Height
Hex Nut Jam Nut Nylock Nut
2 4 1.6 1.2 -
2.5 5 2 1.6 -
3 5.5 2.4 1.8 4
4 7 3.2 2.2 5
5 8 4 2.7 5
6 10 5 3.2 6
7 11 5.5 3.5 -
8 13 6.5 4 8
10 17 8 5 10
12 19 10 6 12
14 22 11 7 14
16 24 13 8 16
18 27 15 9 18.5
20 30 16 10 20
* This is the diameter across the flats. It is also the size of wrench to use.