M14 DIN EN 14399 Part 6 Thru-Hardened Plain Steel Structural Flat Washer / CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 15.00 MILLIMETERS NOMINAL PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 2.50 MILLIMETERS NOMINAL OVERALL DIAMETER: 28.0 MILLIMETERS NOMINAL END ITEM IDENTIFICATION: NSN: 2320-01-529-2251; MRAP BUFFALO MK2A2 PART NAME ASSIGNED BY CONTROLLING AGENCY: MET HARDENED FLAT WASHER M14 MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL