Domed washer by Jonathan Byler

Overall the inside measures about 15/32"  and overall the outside measures about 3/4"  
total thickness is .088" 

layed with the wider side down, the profile is as follows:  straight up 1/32"  then tapers up 
the remaining distance (about .057") until the diameter at the "top" or smaller side is 9/
16" then goes flat across the top 1/32" until the diameter of the inside hole is 15/32"

as to it being domed, it is so slight as to not be obvious to the naked eye.  laying a rule 
across the tapered surface reveals that it is domed, however slightly this is.