Material: Alloy steel has high strength, corrosion resistance, high hardness and long-term stability. Common sizes18 sizes. Suitable for most needs, give a screwdriver. Small screws are suitable for watch covers, glasses frames, notebooks, etc. Ideal for general purpose use which can meet your basic need. Easy to use: Flat head screws are more convenient to tighten, the screw head is sharp, easy to penetrate, suitable for metal plates, plastics, wood and other brittle materials. A convenient storage box: Equipped with a transparent plastic box with multiple partitions to keep each model separate, which makes you convenient to select the right screw type or put it back. After-Sale Service: Each Screw is durable and new designed. If you have any questions when you receive the item, please feel free to contact us any time. We will solve problem within 24 hours.