Steel Fender Washer, Zinc Plated Fastener Finish, Fits Bolt Sizes 5/16 in/ CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 0.344 INCHES NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.051 INCHES NOMINAL OVERALL DIAMETER: 1.25 INCHES NOMINAL END ITEM IDENTIFICATION: 2320-01-531-2701 PART NAME ASSIGNED BY CONTROLLING AGENCY: WASHER,FENDER MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL