Material of The Socket Head Screws Head Socket Cap :Made of high quality 304 stainless steel ,with the features is environment-friendly, no pollution, Anti-corrosion,high hardness,solid and sturdy ,not easy to damage , such as:cold and wet weather. Good for Your Choose: You will get 8800PCS 304 stainless steel socket head screws ,with 20 kinds of different size of M2 M3 M4 M5 M6(Include M2 M3 M4 M5 M6 Nuts and M2 M3 M4 M5 M6 Washer) meet your different needs, It is a very essential hand tool for the family. Easy to Use: Socket head screws assortment kit includes some common metric sizes, M2 M3 M4 304 stainless steel socket head screws are easily and quickly to penetrate various materials, you can use them for plastics, wood, ceramic tile,cement and other materials. An essential hand tool for the family: Widely used in all kinds of manual DIY production, precision machinery industry, 3D printing equipment, instruments, electronic products, household appliances, lamp or toys, etc.