Product Description This IRWIN HANSON 39-Piece Machine Screw/Fractional Tap and Die Set is great for routine maintenance, repair work and for re-threading where high accuracy and tolerance thread is not critical. The taps feature a straight flute that is ground to provide rapid chip removal and efficient threading. They are designed for hand-threading work in various materials and produce a class 2B thread. The taps and dies are made from high-carbon steel for durability. From the Manufacturer Irwin Industrial Tools 23614 39-Piece Machine Screw with Fractional Tap and Solid Round Die Set. A Wide Variety of Great Tap and Die Combination Sets