LuKaiSen 631PCS M3 Hex Socket Head Cap Screws and Nuts Assortment Kit, Grade 12.9 Alloy Steel Metric Machine Bolts (M3 x 6/8/10/12/16/20mm) with Flat Washers & Wrench,Black Zinc Plated for 3D Printing

• 1. GRADE 12.9 ULTRA HIGH TENSILE STRENGTH: Crafted from premium alloy steel, our M3 screws meet the 12.9 grade industrial standard, providing superior tensile strength and hardness compared to stainless steel or 8.8 grade bolts. They are engineered for high-stress applications where durability and reliability are non-negotiable.
• 2. ADVANCED BLACK ZINC PLATED FINISH: Unlike common black oxide fasteners that may rub off or rust quickly, these screws feature a specialized Black Zinc Coating. This finish offers excellent corrosion resistance and a sleek, uniform black look, making them perfect for visible assemblies like PC builds and drone frames.
• 3. ESSENTIAL 631-PIECE METRIC SET: This comprehensive assortment includes 210 screws in 6 frequently used lengths (6mm, 8mm, 10mm, 12mm, 16mm, 20mm), plus 210 matching hex nuts and 210 flat washers. To ensure immediate use, we’ve also included a precision Allen wrench in every box.
• 4. PRECISION HEX SOCKET DRIVE: Designed with deep, standardized internal hex sockets, these cap screws provide a high-torque connection that resists stripping. The clean, burr-free threads ensure smooth engagement and a professional fastening experience for delicate electronics and heavy-duty machinery alike.
• 5. LABELED STORAGE FOR QUICK ACCESS: All 631 pieces are organized in a heavy-duty, transparent storage case with secure snap-locks. A detailed size chart is printed on the lid, allowing you to identify the exact length you need in seconds, keeping your workspace organized and efficient.

Industrial Strength Meets Professional Aesthetics: LuKaiSen 631PCS M3 Black Zinc Screw Kit Why settle for standard hardware when you can use the best? The LuKaiSen M3 Grade 12.9 Assortment is designed for those who build for performance. Whether you are assembling a high-speed FPV drone, a precision 3D printer, or repairing industrial equipment, our high-tensile alloy steel screws provide the clamping force you need with a finish that lasts. The Strength of Grade 12.9: In the world of fasteners, 12.9 is the gold standard for strength. These screws are significantly harder and more resistant to breakage than common stainless steel. They are the ideal choice for mechanical parts subject to vibration or high torque. Superior Black Zinc Finish: We've upgraded the surface treatment to Black Zinc Plating. This process provides a deeper, cleaner black color that won't leave greasy residue on your hands and offers a superior barrier against rust and oxidation compared to traditional black oxide. Full Kit Contents (631 Pieces): Screws (210pcs): M3x6 (50), M3x8 (50), M3x10 (30), M3x12 (30), M3x16 (25), M3x20 (25) Nuts: 210 x M3 Hex Nuts Washers: 210 x M3 Flat Washers Tools: 1 x Allen Wrench Storage: 1 x Labeled Organizer Case Upgrade your toolkit with LuKaiSen today. High-precision hardware for high-performance projects!