2 Asian Hand-Cut Steel Circular Decorative Panels

I would like to know what this kind of art is called (if it has a name), and from what era. I'm pretty sure it's 20th C, but is it pre-war, or more recent?

Each are ~11 inches diameter; the borders are ~⅝" wide. The steel sheet is ~0.5mm thick. They are uniformly black both sides.

Close inspection shows myriad individual chisel cuts along the edges, and every line has a rounded cross-section as if it had been embossed; formed from behind.

 

Very interesting. Haven't seen pieces quite like these before.

 

Tiehua
https://blog.mcdaniel.edu/wuhutiehuacatalog/about/

 

What they brought to mind was Japanese tsuba (sword guards) which, of course, are so much smaller:


From your description, it could be that the metal was stamped and then something like a fret saw used to cut out essentially a silhouette. Do you have a close-up from the backside? I have no idea what these are supposed to look like from behind.