Irwin Industrial Tools 24614 Fractional Tap and Hex Die Set, 24-Piece This tap and die set is designed to ensure that bolts fit tightly and anchor securely High-carbon steel taps and dies help ensure durability Fractional: 1" hexagon: 1/4" - 20 NC, 1/4" - 28 NF, 5/16" - 18 NC, 5/16" - 24 NF and 3/8" - 16 NC Fractional: 1" hexagon: 3/8" - 24 NF, 7/16" - 14 NC, 7/16" - 20 NF, 1/2" - 13 NC and 1/2" - 20 NF; Pipe: 1" hexagon: 1/8" - 27 NPT Threading tools: Plain die stock - 1" dies and offset adjustable tap wrench - taps #0 to 1/2" 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.