General description The 49 Piece Thread Repair Kit is a comprehensive toolset designed for repairing worn and damaged threads. It effectively removes stubborn dirt and corrosion while maintaining the integrity of the metal. This kit is ideal for use on rusty fasteners, bolt holes on automotive cylinder heads, engine blocks, and vehicle bodies. The set features color-coded tools for easy identification: silver for UNC, black for UNF, and gold for metric sizes. Each compartment in the storage box is labeled with the specifications, allowing for quick access to the right tool. Technical specifications Material: 45# Carbon Steel Number of pieces: 49 24PCS Dies: National Coarse (NC) Sizes: 1/4"-20, 5/16"-18, 3/8"-16, 7/16"-14, 1/2"-13, 9/16"-12, 5/8"-11 National Fine (NF) Sizes: 1/4"-28, 5/16"-24, 3/8"-24, 7/16"-20, 1/2"-20, 9/16"-18, 5/8"-18 Metric Sizes: M6x1.00, M8x1.25, M10x1.0, M10x1.25, M10x1.50, M11x1.5, M12x1.25, M12x1.5, M12x1.75, M14x1.5mm 22PCS Taps: National Coarse (NC) Sizes: