Metric & Inch Nut and Bolt Thread Checker — Identify Threads Before Buying Replacements

🔩 Metric & Inch Nut and Bolt Thread Checker — Identify Threads Before Buying Replacements

Found a loose bolt or an unmarked nut in your parts bin? This thread checker helps you identify its thread size by matching it to a labeled gauge. Use the internal thread to check bolts and the external thread to check nuts. Thread parts on gently by hand; never force a match.

🔴🔵 Separate Metric and Inch Sizes at a Glance

Red gauges identify metric sizes, while blue gauges identify inch sizes. The contrasting colors help narrow your search when sorting mixed hardware from garage projects, bicycle maintenance, or household repairs. Read the size marking once you find a smooth thread match.

🛠️ Remove a Gauge When You Need More Room

The detachable wire loop lets you take individual gauges off for separate use, so you can work without handling the entire set. Reattach the pieces and secure the end fitting afterward to keep your thread references together.

📏 Check 14 Inch Thread Sizes

Compare both diameter and threads per inch to distinguish similar-looking fasteners. The listed inch sizes are: 6-32, 8-32, 10-24, 10-32, 1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 7/16-14, 7/16-20, 1/2-13, and 1/2-20.

⚙️ Add 12 Metric Sizes to Your Reference Set

The listed metric sizes are: M4-0.7, M5-0.8, M6-1.0, M7-1.0, M8-1.0, M8-1.25, M10-1.0, M10-1.25, M10-1.5, M12-1.25, M12-1.5, and M12-1.75. Together with the inch gauges, these provide 26 labeled thread references for organizing hardware and identifying replacements. Also match the replacement fastener's length, head style, and grade to the job.