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: 0.380 INCHES NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.102 INCHES NOMINAL OVERALL DIAMETER: 0.887 INCHES NOMINAL END ITEM IDENTIFICATION: R19TM900GPMFL PART NAME ASSIGNED BY CONTROLLING AGENCY: 5/16" FLAT WASHER, THRU-HARDENED HIGH STRENGTH COLOR: YELLOW OVERALL MATERIAL: STEEL OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: ASTM F436 ASSN STD SINGLE MATERIAL RESPONSE OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: ASTM B633 ASSN STD SINGLE TREATMENT RESPONSE OVERALL