Nut & Bolt Thread Checker: Inch & Metric The Inch & Metric Thread CheckerTM is an accurate and easy-to-use thread identifier for both nuts and bolts. Each individual gauge features a male threaded stud on one end and a female threaded hole on the other. The Thread Checker is especially well suited for distinguishing between similar inch and metric threads. Conveniently assembled onto a wire loop, it"s the perfect portable solution! Hang it on your shop wall or store it in your tool box for safe keeping. The Thread Checker, also known as a Thread Identifier or Thread Verifier is a great addition for any Home, Hobby, or Inventor"s Work Shop; Auto, Motorcycle, Marine, ATV or RV Repair Shop; Heavy Equipment Repair Shop, Military Equipment Repair Station, Machine Shop, Fabricating Shop, Assembly Department, Production Department or Quality Inspection Station! SIZE SPECIFICATIONS: INCH (14): 6-32, 8-32, 10-24, 10-32, ¼-20, ¼-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 7/16-14, 7/16-20, ½-13, ½-20 METRIC (12): M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8x1.25, M10x1.0, M10x1.25, M10x1.5, M12x1.25, M12x1.5, M12x1.75 Proudly Made in the USA!