I find these hangers very useful and I suppose they can be made by hand but I found that the size varies from hanger to hanger so I made this adjustable jig which makes them exactly to size.
This jig is about 15 years old and has made thousands of rings hence its rather battered appearance.
The jig is made from three wood components I have marked them A B & C
A is screwed to C the base and B is the slide which is adjustable so that different size rings can be made
A has a pin bent at 90 degrees and B has an upright pin
I use a softish 2.5 mm dia wire as it makes for easier handling. The wire is straightened by placing one end into my hand drill chuck and firmly anchoring the other end (wear safety glasses) I straighten a 4 meter piece of wire at a time . Pull the wire taught and and rotate the drill for about 10 seconds , do not exceed this as it tends to make the wire brittle
The ring I have made here is for a 165 mm pot so I cut the wire to 620 mm lenghts.
The slide is now opened so that the ends lie on the markers.
bend the wire around the 90 degree pin first.
pull the wire taught once you have compleated bending and then bend the wire around the upright pin
You will note that I have holes drilled 20mm from each pin. I insert a bending pin into these holes and bend the ring wire around these
You can now remove the ring wire from the jig and wrap around a tin which has a smaller dia than the size of the ring you are making
Slot the ends together and bend the tops over and you have your ring