This article describes one method of forging field-frame rings from flat steel.
NOTE: You are strongly encouraged to forge oval field-frame rings following these instructions instead.
Making steel field-frame rings Edit
First you need a template around which you'll forge the rings. The same template used for washer rims works great:
In general, you can follow the same procedure as when forging steel washers. There are two exceptions though. First, don't bend the bar into a perfect circle: rather, make sure the ends of the bar meet each other at 90 degree angle:
This makes the ring wider and provides more space for attaching one of the field-frame bars. To provide extra space for the other field-frame bar, flatten the opposite end of the ring slightly. The result should look something like this:
After forging the surface of the ring which will touch the washer rim has to be ground perfectly flat. The process is the same which is used to polish washer rims:
Note that in the above picture shows a washer rim, not a field-frame ring.
Finally, file a groove to the joint and weld the ends of the ring together:
Grind excess steel away. Finally polish the ring using sandpaper of always increasing fineness, up to 800 grit. Please disregard the fact that this polished ring is actually oval and that it has been already attached to the field-frame bars: