How To Measure Thread Size And Pitch. They are measured by the number of threads per inch or the distance between threads on metric thread types. Measuring threads using the thread pitch gauge, align the gauge on the threads and make sure it is snug.
Second measure the pitch pitch is threads / per unit. The thread pitch is the distance between threads expressed in millimeters (measured along the length of the fastener). A steel rule, caliper, or comparator are the most common measuring instruments used to determine thread pitch.