Is it a tax token or a train token?

[Arkansashunter]

It weighs 1 .10 g non ferrous any ideas would be helpful can't make out any but a a 17

 

[jim tn]

Just the 17 for writing? Maybe give it a brief vinegar with a dollop of salt soak. To me, it actually looks like a washer or sorts. HH jim tn

 

[Arkansashunter]

Just the 17 for writing? Maybe give it a brief vinegar with a dollop of salt soak. To me, it actually looks like a washer or sorts. HH jim tn

Will do ty so much

 

[Ronstar]

Thinking washer where electrical contact critical. Interesting piece!

 

[407floyd]

I'm going with specialized washer.