Stainless Steel Flat Washer, Plain Fastener Finish, Fits Bolt Sizes M8, 16 mm Washer Outside Dia./ CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 8.4 MILLIMETERS NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 2.5 MILLIMETERS MINIMUM AND 3.4 MILLIMETERS MAXIMUM OVERALL DIAMETER: 16.0 MILLIMETERS NOMINAL END ITEM IDENTIFICATION: STRYKER HARDNESS RATING: 70.0 ROCKWELL B NOMINAL PART NAME ASSIGNED BY CONTROLLING AGENCY: FLAT WASHER MATERIAL: STEEL PROPERTY CLASS 18.8 OVERALL