High quality 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 wood screws: M3*4/5/6/8/10/12, Each 55 Pieces, M3*14/ 16/18/20/25/30,Each 30 Pieces,Include 300 Pieces Flat Washers,300 Pieces Nut,to meet different needs.It is a very essential manual tool for the family.With M3 nuts and washers , the installations are now more precise with an increase in the contact surface, which reduces the pressure and protects the parts and the screws. The stainless steel screws, nuts and steel washers are arranged in a storage box, this which allows you to easily find yourself in the series and avoid loss when necessary. The main use of the stainless steel screw is very common in electronics, for electrical appliances, chemicals, l water, machinery and equipment, furniture and many other areas.