61-Piece Complete Professional Kit: 28 Dies + 28 Taps + 3 Thread Files + 2 Pitch Gauges - Covers 95% Automotive/Industrial Thread Repairs (Cars, CNC Machines, Pipes) 3-Second Color Identification System: Instant Standard Recognition, Silver=UNC (5/8"-11 to 1/4"-20), Black=UNF (5/8"-18 to 1/4"-28), Gold=Metric (M6-1.0 to M14-1.5) Industrial 40CR Carbon Steel Construction: High-carbon steel tools are heat-treated to a hardness of 58 HRC - rust and wear-resistant for longer tool life than ordinary repair kits Organization Case: Impact-Resistant Toolbox with Custom Molded Slots - Securely Holds 61 Tools in 3 Color-Coded Zones (UNC/UNF/Metric) Dual Standard Compatibility: Repairs SAE & Metric Threads in One Kit. From 5/8"-18 Automotive Bolts to M14-1.5 Hydraulic Fittings - No Additional Tools Needed ProSeries 61-PCS Thread Repair Kit SAE & Metric, 40CR Carbon Steel Thread Restorer Tool Set with Color-Coded Dies/Taps, for Damaged Threads Repair in Automotive, Machinery, Plumbing (UNC/UNF/Metric)