5/16" x 0.875" OD Thru-Hardened Yellow Zinc Finish Steel USS General Purpose Flat Washer / CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 0.375 INCHES NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.093 INCHES NOMINAL OVERALL DIAMETER: 0.875 INCHES NOMINAL END ITEM IDENTIFICATION: MRAP - COUGAR SPECIAL FEATURES: 5/16 INCH USS ZINC PLATED THROUGH HIGH STRENGTH FLAT WASHER MATERIAL: STEEL OVERALL PROPRIETARY CHARACTERISTICS: NPAC SURFACE TREATMENT: ZINC OVERALL