In order to reach a chromed-level shine on my metal pieces, I use a buffing wheel.
Buffing wheels work well to get off shallow scratches. I haven’t found them to be quickly effective on the straight-from-the-factory sheet metal, which sometimes has a bit of a glossy sheen to it.
Instead, I use a series of sandpapers with increasing grit (220 to 1000) to rough up the surface uniformly, then take it to the buffing wheel to polish.
I keep the buffing wheel prepped with black wax, which I apply by touching the wax stick to the spinning wheel.
If the piece gets hot in process, I will wrap the part that I’m not polishing in painters’ tape to provide an insulating buffer.
Here you can see the drastic difference between the just-sanded and sanded+polished sides.
Buffing wheels! One of my favorite tools in the shop.