M4 x 9mm OD DIN 125 Grade HV200 Zinc Finish Steel Type A General Purpose Flat Washer / CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 4.3 MILLIMETERS NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 1.1 MILLIMETERS NOMINAL OVERALL DIAMETER: 12.0 MILLIMETERS NOMINAL END ITEM IDENTIFICATION: 2355-01-567-4930 MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL