Key operators may strike against it (6)
I believe the answer is:
platen
'key' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for platen that I've seen before include "Roller against which typewriter keys strike - ten lap (anag)" , "One working in the press" .)