Features:Size: M3.5/4.2/4.8 screws with matching cross nuts, lock washers and flat washers, which can meet your different needs.Material: Carbon steel material which have good corrosion resistance in bad environment like high temperature, cold weather, and high humidity areas. Thus, the screw set can serve you for a long time.Package: 340 pieces in total, packed in a durable transparent box. It is easy to distinguish the size of the product, when you want to use a certain screw.Wide Applications: Widely used in all kinds of precision machinery industry, classified instruments, instruments, electronic products, printed projects, household appliances, communication products.Long Service Life: The installation parts can be used continuously, bear strong load and have a long service life.Specifications:Material: Carbon steelProduct Quantity: 340pcsSurface Treatment: UntreatedApplication: Widely used in machinery, electrical appliances and buildings.includes:50PCS * M3.5X9.560PCS * M3.5X1350PCS * M3.5X1640PCS * M3.5X1930PCS * M4.2X1340PCS *M4.2X1630PCS * M4.2X1940PCS * M4.8X13