The medallions on my workshop saws are made from silver, this makes a nice contrast with the black American walnut. Brass was used traditionally, and I use brass on my site saws in combination with English beech, as they don't mind being treated a bit rougher.
My wife is a trained silversmith, which means that I have all the specialist tools to hand.
Having pierced the silver sheet to the required pattern, it is then soldered onto a second sheet of silver. This is then cut to the correct diameter, before polishing and fixing to the brass threaded bar.
The design on the medallions is based on the geometry of the daisy wheel. The daisy wheel is a geometrical symbol used by medieval builders to set out buildings and carpentry. It can be used to create angles and transfer complicated proportions, without the need for plans with dimensions, to craftsmen who were often highly skilled but illiterate.
The medallion and brass studs are polished and finished. The brass studs are made from 5/8th brass stock and threaded bar. The traditional split brass nuts are also made from the same 5/8th stock.