In earlier years I bought my valve hand wheels or milled them from a disc. Since some time I make filigree handwheels myself.
Starting material is thin brass tube and hexagonal brass.
6 tubes are arranged around the hexagonal material and held together with two rings at the ends. This package is coated with flux and soldered with the flame and silver solder. The rings are not soldered together.
Slices are then cut from this package with the band saw and machined.
The diameter of the hand wheels is 18mm.
The tube diameter is 6mm outside, 5mm inside. Hexagonal material 6mm wrench size.