M20 x 37mm OD DIN 125 Grade HV200 Zinc Finish Steel Type A General Purpose Flat Washer / CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 21.0 MILLIMETERS NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.3 MILLIMETERS NOMINAL OVERALL DIAMETER: 37.0 MILLIMETERS NOMINAL END ITEM IDENTIFICATION: MRAP - COUGAR SPECIAL FEATURES: GRADE HV200/125 HARDENED MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL