| Screw Dia | M3 | M4 | M5 | M6 | M7 | M8 | M10 | M12 | M14 | M16 | M20 | M24 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Head Wd., mm | 5.5 | 7 | 8 | 10 | 11 | 13 | 17 | 19 | 22 | 24 | 30 | 36 |
| Head Ht., mm | 2 | 2.8 | 3.5 | 4 | 4.8 | 5.3 | 6.4 | 7.5 | 8.8 | 10 | 12.5 | 15 |
Comparable to US Grade 8, Class 10.9 bolts are generally used for the same application. These are made
from either a medium carbon or an alloy steel and have a black finish. Manufacturer and strength
class are marked on the top of the head. Minimum tensile strength is 150,000 psi. Bolts are threaded
at least two times their diameter + 6mm. Length is measured from under the head.