【Product details】- This M3 countersunk screw assortment kit comes with 650 pieces, including 350pcs M3 bolts, 300pcs nuts. This M3 screw set is ideal for electronics, RC models, DIY repairs, home repairs and machinery. 【Standardized Metric Sizes】 -The M3 phillips flat head screws set come with 7 commonly used lengths—M3-0.5 x 4mm, 6mm, 8mm, 10mm, 12mm, 16mm,20mm. Thread pitch=0.5mm —ideal for routine installations and repairs. They meet standard metric specs, the average error is less than 0.01mm. 【Premium 8.8 Grade Alloy Steel】- This M3 phillips flat head bolts and nuts assorted kit are crafted from high-strength grade 8.8 alloy steel, ensuring exceptional durability and load-bearing capacity. High-strength steel resists wear, corrosion, and heavy loads, perfect for any indoor/light outdoor use. 【Oil-Free & Rust-Proof】 -Black zinc plating means no greasy mess—keep hands and projects clean. Superior rust resistance ensuring long life.This 3mm black machine screw set ensures a cleaner handling experience and long-lasting performance even in humid or demanding conditions. 【Smart Storage Box 】- The metric machine flat head screws fasteners kit comes in a durable, compartmentalized case with clear size labels—so you can spot the right screw instantly. Keeps your workspace tidy and speeds up project progress, making every job smoother. Fgruh 650pcs M3 Countersunk Screws Assortment Kit, M3x4/6/8/10/12/16/20 mm Phillips Flat Head Bolts and Nut Assorted Set, Machine Screws Grade 8.8 Alloy Steel Black Zinc Plated