1600Pcs Metric Screw Assortment M2 M3 M4 M5, Grade 12.9 Alloy Steel Metric Bolts ?Well-made Metric Bolts and Nuts Assortment? : 100% made of high quality 12.9 grade alloy steel, high strength, superior rust resistance and excellent oxidation resistance, perfect for all weather use. Metric screw assortment conforms to the standardized metric system, the average error is less than 0.01 mm. ?1600pcs 16 Standard Size?: Various M2 M3 M4 M5 screws and bolts with lock flat washers, total 16 sizes : M2 screws: bolt length: 4mm,6mm,10mm,12mm, M3 screws: bolt length: 6mm,8mm,12mm,16mm, M4 screws: bolt length: 8mm,12mm,16mm,20mm, M5 screws: bolt length:12mm,16mm,20mm,25mm, 1600pcs in total, meet all demands. 4 hex wrenches customized for each size are provided in the kit to make the screws easier to use. ?Upgraded Zinc Plated Screw Set?: All screws without adding any anti-rust oil, featuring upgraded black zinc plated, extend the rust-proof time, cleaner and tidier. It is an ideal choice whether for your own use, or as a gift for family or friends. ?Nice Storage Box?: The bolts and nuts kit are packed in a reinforced box with separate compartments and sturdy latches, clean and neat, keep everything well organized, easy to store and carry, clear label sheets are pasted on both the inner and outer lids, allowing you to quickly see which sizes you need to use and refill. ?Wide Applications?: This metric bolt assortment can be widely used in all kinds of precision machinery, 3D printers, electronics, home appliances, toys, etc. We offer a 24-month warranty, contact us freely if you have any problems and questions.