Package Includes: 7 sizes of M3 / M4 / M5 / M6 / M8 / M10 / M12 in total 340 pieces, in a transparent box, applicable to different sizes of fasteners. High Quality Materials: Made of 65Mn metal steel, black oxide finish, no burr, provides good corrosion resistance and high temperature resistance. 7 Size: 340pcs starlock washer set includes 7 most used sizes , M3 / M4 / M5 / M6 / M8 / M10 / M12, all washers will be packed in a strong transparent plastic case, can be used for storage box. Working Principle: One washer brake exerts a spring force between the head of the fasteners and the substrate, which keeps the washer hard against the substrate and the bolt thread hard against the nut or thread of the substrate, creating more friction and resistance to rotation . Wide Range of Applications: Used in machinery equipment, industrial shock absorption production and insulation, can meet your different needs in daily life. Assortment sets of high quality internal tooth Starlock washers, perfect for quick fixes and very simple repair. Product -7 size of M3 / M4 / M5 / M6 / M8 / M10 / M12 total 340 pieces, in a transparent box, applicable to different sizes of fasteners. -Made of 65Mn metal steel, black oxide finish, burr-free, with good corrosion resistance and high temperature resistance. -High quality Internal Tooth Starlock Washer Assortment Sets, perfect for quick repairs and very simple repair. -Used in machinery equipment, industrial production of shock absorption and insulation, can meet your various needs in daily life. Specifications: Material: 65Mn Metal Steel Color: Balck Sizes : M3 / M4 / M5 / M6 / M8 / M10 / M12 Quantity: 340 pieces Package Includes: - M3 - 60 pieces - M4 - 60 pieces - M5 - 60 pieces - M6 - 50 pieces - M8 - 50 pieces - M10 - 40 pieces - M12 - 20 pieces