Looks like an adjuster for leveling a platen. I can't think of anything in brass but I'll guess for a 3D printer.

It is adjusting something, which in normal cases would be visible in this photo.

But it's not part of a printer.

A clock adjuster?

Does it adjust/regulate the speed of some kind of motor?

No to both.



There is usually six of these on the object it sits on.

Six cylinders?

I'm stumped right now waiting for an unconscious epiphany.

Is that middle photo a spring?

It is simply a screw and a spring and a moving part. Six of these usually.

Good! My previous one you solved in like 20minutes 😊

Yes.



The bottom part is the part that moves when tensing the screw.

Something is not present in the photo, which normally would be there and make it fairly obvious what it is.

Do these screws adjust the angle of a blade or blades?

No.

Is it something used in an office?

One of the six bridge adjusting screws on an electric guitar?