Flat Washer: Class 4.8, Chrome Plated, Steel, M5 Screw Sz, 5.48 mm In Dia, 10 mm Out Dia, 10 PK

General purpose metal flat washers provide a smooth surface under the head of a nut or bolt to prevent loosening and damage to the work surface. These round washers also minimize heat and friction while installing a threaded fastener.