This is a cast iron 8" cast iron drop in grate. The exact size specs of the grate are listed below:
Grate face diameter: 9.875"
Grate face thickness: 0.75"
Drop in outside diameter: 7.75"
Drop in inside diameter: 7.00"
Drop in length: 1.50"
The grate is in new unused condition, the part was job surplus.