Steel Flat Washer, Zinc Plated Finish, DIN 125, Metric, M20 Screw Size, 21 mm ID, 37 mm OD, 3 mm Thick (Pack of 25): Amazon.com: Industrial & Scientific
20pcs) DIN 125 M52 Flat Washers (54mm ID) Type A A2 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP01252540: Amazon.com: Industrial & Scientific