Specification - Product Type: M6 Black Flat Washer; Color: Black; OD: 17.7mm; ID: 6.3mm; Thickness: 1.9mm; Package Quantity: 50 PCS. Material - Made of Stainless Steel 304, Black Finish. Performance - 304 stainless steel has great corrosion resistance in bad environment such as high temperature, cold weather, and high humidity areas, and also has superior rust resistance, excellent oxidation resistance and long service life; The stainless steel flat washer has a black oxide finish which offers nice appearance and lubrication; Easy to install. Function - Flat washers are used under the head of a bolt or nut across the area of the support to prevent pulling through. Widely Application - Apply for electronics, machinery, automotive, marine uses, industrial, furniture, etc. The function of flat washer is to reduce friction, prevent leakage, isolate and prevent loosening or dispersing pressure; They are applied in many materials and structures; Because of limitations of the material and workmanship of threaded fasteners, the support surface of the fasteners such as bolts is not large enough; Therefore, in order to reduce the compressive stress of pressure-bearing surface and protect the surface of the connected object, flat washer is applied.