Any ideas?

[Ludlow6]

Not sure what this is.

 

[EmuDetector]

maybe a heel plate from in a shoe?

 

[hoser]

Is it steel, or a soft metal?

 

[kingman mikey]

Piece of metal on top of a knee

 

[stetam]

Looks like the plate off the bottom of a driver

Steve

 

[Wolf-Dog]

maybe a heel plate from in a shoe?

X2 on heel plate.

 

[Ludlow6]

Is it steel, or a soft metal?

Its copper or brass

 

[hoser]

Ok since it is copper or brass it resembles a metal seal plate that would be used at a plug or access point on a high pressure, high temp steam pipe. Soft metals are used as they won't blow out under high pressure, and they deform to any irregularities in the sealing surfaces allowing for a precise fit. I said it resembles this plate but it's still just a guess.