6pcs Magnetic Triangle Screwdriver Bits S2 Steel 1/4 inch Hex Shank Screwdriver Bit Set DIY Hand Tools Features: 1. Made of high quality S2 alloy steel with hardness of 58-60HRC 2. After heat treatment, it is superhard and wear-resistant, which is more than twice the life of the same product. 3. It is the most ideal industrial grade mouthpiece for factory assembly line. 4. High-intensity magnetic bit is suitable for electric screwdriver, hand drill, charging drill, etc.