EXTSW 5/8” ID x 1.950” OD x 1/4” thick 316 beveled stainless washer
Actual size .640" ID x 1.950” 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.