Milestones:Plaque mounting details
From ETHW
Milestone plaque mounting details
The milestone plaques come with six mounting holes in the back. There are four at the corners 2.75 inches/6.5 cm in from the corners (as measured on the diagonal) and two holes along the mildline (6 inches) of the plaque 4 inches/10 cm in from the side edges. The plaques come with six threaded bolts ½ cm in diameter and 5 cm long. Below is a rough diagram of the plaque as seen from the back.