About this item Built to Last: Our thread chaser set is crafted from premium steel with a finely ground surface, HRC 55-62. This ensures excellent corrosion resistance and long-lasting durability, making it a reliable tool. 49-Piece Precision Repair Set: This rethreading tool kit is designed to trace and repair worn or damaged threads. It serves as both a thread restoration and cleaning tool, effectively removing stubborn dirt and corrosion without compromising thread integrity. The 49-piece kit includes 24 dies, 22 taps, and 3 thread files, designed to restore threads on rusted fasteners as well as bolt holes on cylinder heads, engine blocks, and other vehicle components. Comprehensive Size & Color-Coded Design: The thread chaser kit includes three standards (UNF, UNC, and Metric) with color-coding for quick visual identification. UNC (Silver): 5/8"-11, 9/16"-12, 1/2"-13, 7/16"-14, 3/8"-16, 5/16"-18, 1/4"-20; UNF (Black): 5/8"-18, 9/16"-18, 1/2"-20, 7/16"-20, 3/8"-24, 5/16"-24, 1/4"-28; Metric (Gold): M14x1.5, M12x1.75, M12x1.5, M12x1.25, M11x1.5, M10x1.5, M10x1.25, M10x1.0, M8x1.25, M6x1.0. Convenient Storage Case: The thread repair kit includes a carry case to keep all your thread repair tools neatly organized, and allows for easy transport from one job to the next, ensuring a hassle-free experience. 3 Thread Files with Removable Plastic Covers: The thread files of our thread restorer kit come with removable plastic covers to shield the cutting edges and protect your hands during use. SAE Thread File 1: 9 - 10 - 12 - 16 - 20 - 27 - 28 - 32; SAE Thread File 2: 11 - 12 - 13 - 14 - 16 - 18 - 20 - 24; Metric Thread File: 0.75mm - 1.0mm - 1.25mm - 1.50mm - 1.75mm - 2.00mm - 3.00mm.