This stainless steel metric screw assortment series provides a complete fastening solution for mechanical assembly, home maintenance, electronics, and 3D printing projects. Each kit includes a wide selection of button head socket cap screws made from durable 304 stainless steel, offering strong corrosion resistance, reliable fastening strength, and long service life. The assortments cover commonly used metric sizes from M2 to M6, supporting both precision work and general-purpose installations.The 159-piece set focuses on M6 screws in multiple lengths, paired with matching nuts, washers, and hex wrenches for immediate use. The 900-piece assortment includes M3, M4, M5, and M6 sizes, making it suitable for device repair, furniture assembly, and daily workshop needs. The 1290-piece set provides small-diameter screws from M2 to M5, ideal for electronics, robotics, micro-mechanisms, and 3D printer maintenance.Each screw features clean, accurate threads and a smooth button head that offers a neat, low-profile finish. All components are organized in a divided storage box, keeping items separated and easy to access. Designed for indoor and outdoor environments, these 304 stainless steel fasteners resist rust, moisture, and oxidation, ensuring stable performance for long-term repair, assembly, and replacement tasks.