Irwin Industrial Tools 23614 Machine Screw with Fractional Tap and Solid Round Die Set, 39-Piece This tap and die set features high-carbon steel construction for durability These taps and dies are great for routine maintenance, repair work and re-threading These taps are designed for hand-threading work and produce a class 2B thread Machine screw: 1" solid round: 4 - 40 NC, 6 - 32 NC, 8 - 32 NC, 10 - 24 NC, 10 - 32 NF and 12 - 24 NC Fractional: 1" solid round: 1/4" - 20 NC, 1/4" - 28 NF, 5/16" - 18 NC, 5/16" - 24 NF, 3/8" - 16 NC, 3/8" - 24 NF, 7/16" - 14 NC, 7/16" - 20 NF, 1/2" - 13 NC and 1/2" - 20 NF We're working with a variety of tradesmen to solve endless fastening challenges: Irwin Hanson Taps and Dies are the answer. Whether creating new tools from raw steel or repairing damaged and worn threads, achieving a precise fit is essential. Irwin Industrial Tools sets the standard for delivering quality every step of the way in your threading applications.