EXTSW 5/8” ID x (2” / 1.990”) OD x 1/4” thick 316 Beveled stainless washer
Actual size .632" ID x 1.990” OD x .250" thick  
(+/- .003" on all dimensions) 
.030 inch Radius OD / slightly countersunk ID (no sharp edges)
Made in USA. 316 Stainless has the ULTIMATE corrosion resistance.