Kit sizes: hex head screws included: M3x10, M3x20, M3x30, M4x10, M4x20, M4x30, M5x10, M5x20, M5x30, M6x10, M6x20, M6x40. 120 screws, 120 nuts, 140 spring washers, 140 pucks. 520 pieces in total. 304 Stainless Steel: The hex bolts are made of high quality and durable 304 stainless steel with excellent corrosion resistance, heat resistance, cold resistance and high toughness. EXQUISITE CRAFTSMANSHIP Our well-engineered nuts and bolts are the perfect pair for great results. And the wire is smooth, sharp and burr-free. Well Organized: All screws and accessories are organized in a sturdy plastic box with compartments, making it easy to find the parts you need. WIDE APPLICATION: Our assortment of M3 m4 m5 m6 bolts, nuts and washers are suitable for indoor and outdoor use, home and work, construction, furniture, automotive, bicycle, in the assembly of ships and more.