Anyone tell me what these tags were used for. They are about 1 3/8" in diameter.

Up Union Pacific Railroad Brass Tag U P T R 6 F Omaha | eBay
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UP UNION PACIFIC RAILROAD BRASS TAG - U.P.T.R.6 F OMAHA in Collectibles, Transportation, Railroadiana & Trains | eBay.

I have found similar tags with my metal detector. Baggage Tags?

Union Pacific Tool Room. Used when you check out tools. Worker gets it back when tool is returned.

Thanks Michael, UPTR = Union Pacific Tool Room makes perfect sense!

I would agree with Michael. The Army used to issue tags at the motor pool, similar to those and when the tool was returned you got the tag back.
However, I am wondering about the one with the hole in the middle.

Thanks for info!!!