M6 Heavy Duty Flat Washers (DIN 7349) - A2 Stainless Steel: Accu.co.uk: Washers & Spacers
Amazon.com: (400pcs) DIN 7349 M10 Washers (10.5mm ID) for Bolts with Heavy Type Spring Pins A4 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP73494105 : Industrial & Scientific