? 304 high quality stainless steel. Stainless steel is a common material with a density of 7.93 g / cm3, also known as 18/8. It has good workability and high toughness up to a temperature of about 800 degrees. ? Different sizes Plates Washer, to meet different needs.It is a very essential manual tool for the family. ? With Flat Washers, the spring washer device is used 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 surface. ? The Dish Washers are arranged in a storage box, so you can easily find your way around the sets and avoid loss when needed. ? Application: Perfect for electrical connections on household and commercial appliances, automotive and marine uses where the power source has a threaded / bolt-type connection.