High quality 304 stainless steel. Stainless steel is a common material with a density of 7.93 g/cm3, also called 18/8. It features good workability and high toughness up to a temperature of about 800 degrees. Various Sizes of Flat Washers: M2 120PCS, M2.5 120PCS, M3 120PCS, M4 120PCS, M5 70PCS, M6 50PCS, M8 50PCS, M10 22PCS, M12 12PCS, to meet different needs. It is a very essential manual tool for the family. With the Plate Washers, the spring washer device is employed under the nut to prevent the nut from loosening. Grower washers are used for loosening, flat washers have no loosening function, and flat washers only increase the contact area. Flat Washers are arranged in a box storage, making it easy to find your way around the series and avoid loss when needed. Application: Perfect for electrical connections on household and commercial appliances, electrical applications; automotive and marine where the power source has a threaded/bolt-type connection. 9 Sizes:(ID x OD x Thickness) M2 (120 Pieces)M2 .5 (120 Pieces) M3 (120 Pieces)M4 (120 Pieces) M5 (70 Pieces) M6 (50 Pieces) M8 (50 Pieces) ) M10 (22 Pieces) M12 (12 Pieces) Application Perfect for electrical connections on household and commercial appliances, automotive uses and marine in which the power source has a threaded/bolt-type connection. Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.