Cut and Repair Metal Threads Yourself: With 8 taps, 8 dies in a full range of sizes from 3 mm to 10 mm, MIBRO 26-Piece SAE Tap, Die and Drill Set is a premium, precision tool kit for hand cutting and repairing of metal threads in your home, workshop or garage. These tapered plug taps and dies are the most commonly used style and are perfect for most hand threading applications. They start easily, either cutting new material or chasing lightly damaged threads. With proper technique and the right lubricant, these taps and dies will cut mild carbon and alloy steel, cast iron, aluminum, brass and bronze. Maximized Durability and Usability: The cutting pieces of this tap and die set feature high strength GCr15 alloy tool steel construction with a titanium coating, allowing them to cut through metals including cast iron, aluminum, brass, and carbon steel, while maintaining their durability and rust resistance. The taps and dies are sized from #6 to 7/16 in. and feature coarse (UNC) and fine (UNF) thread designations, ensuring usability in many hand threading applications. Titanium-coated High Speed Steel drill bits allow for drilling into new materials for fresh tapping or to bore out completely worn threads that cannot be repaired.