Material & Durability of Allen Wrench Drill Bit Set: This allen wrench drill bit set is forged from high-grade S2 alloy steel and treated with vacuum high-frequency quenching, reaching 58-60 HRC hardness. It maintains durability and precision even under heavy-duty use, and its magnetic design avoids bit slippage during operation. Precision of Metric Hex Bit Set: Siemens CNC integrated processing shapes this metric hex bit set for superior molding, enhancing size precision and standardization. High concentricity ensures stable performance, achieved through strict material selection and processing standards. Protection & Identification of Hex Driver Set: The black phosphate finish on this hex driver set adds corrosion resistance. Each bit features clear laser-etched size/type markings for quick identification, and the magnetic tip enables secure connection with screws. Comprehensive Sizing: This hex bit set includes 10 metric sizes (1.5mm–8mm) and 10 SAE sizes (5/64"–5/16"), all 2 inches (50mm) long, meeting diverse assembly and repair needs. After-Sales Support of Hex Driver Set: We provide professional after-sales service for this hex driver set—contact our team anytime for product-related questions, and we will respond and resolve issues promptly. The PTSLKHN allen wrench drill bits are the perfect addition to any DIY enthusiast's tool collection. Made of high-quality S2 alloy steel and processed using CNC precision technology, these bits are capable of withstanding intense pressure and wear.