General description Made of heavy-duty industrial-grade tungsten steel, this 40Pcs M3-M12 Steel Metric Tap and Die Set is designed for high strength and durability. These tools are ideal for creating threads on steel, stainless steel, and other soft materials. The set comes in a molded storage box, making it convenient for re-threading fasteners and fixing holes, suitable for both auto and mechanical repair. Perfect for both professional and amateur craftsmen, these taps and dies are known for their ease of use and are the most commonly used style for hand threading applications.