The thread plug gauge is a tool for measuring the accuracy of the internal thread size. The material is usually made of GCr15 bearing steel, and the high-quality material is tungsten steel.
When choosing a thread gauge, you should choose a specification that matches the measured thread. Before use, clean the oil, impurities, etc. on the surface of the thread gauge and the measured parts to avoid affecting the measurement accuracy.
When using, align the through end (stop end) of the thread gauge with the measured thread, and use the thumb and index finger to turn the thread gauge or the measured part to make it rotate in a free state. Under normal circumstances, the through gauge of the thread gauge can be rotated at any position of the measured thread. If it passes through the entire thread length, it is judged as qualified, otherwise it is an unqualified product; after the stop gauge of the thread gauge is aligned with the measured thread, it is qualified if the screwed-in thread length stops between 2 pitches. It cannot be forced to pass, otherwise it will be judged as an unqualified product.
When inspecting the workpiece, the rotating thread gauge cannot be twisted hard. Use three fingers to rotate naturally and smoothly until it stops. The thread gauge cannot be pulled out forcefully when withdrawing from the workpiece, which will affect the error of the product inspection result.
After use, clean the surface attachments of the through end (stop end) of the thread gauge in time and store it in the measuring tool box in the tool cabinet.