26piece thread checker set including 14 metric sizes A practical tool for engineers, mechanics, auto technicians, and machinists to quickly identify nut and bolt thread sizes for a wide range of applications, saving time and reducing guesswork. Crafted from carbon steel for durability, these thread checkers resist wear and maintain hardness through frequent use in demanding work environments. Compact and portable design: Unlike bulky wallmounted gauges, these thread checkers fit into tight spaces. A included storage case keeps all 26 pieces organized and ready to use wherever needed. Easy, quick identification: Simply thread a nut or bolt onto the corresponding gauge to determine its size, improving efficiency in automotive , machinery maintenance, and general mechanical work. Suitable for automotive and service, industrial machinery maintenance, and onsite field service or DIY projects.