You can use a thread gauge to measure the thread pitch, or you can use a caliper to measure it.

When measuring with a caliper, it is generally not easy to measure a pitch accurately. You can use a caliper to clamp 10 thread pitches at a time to measure, or you can set the caliper at 10mm, remove the thread pitch, and see how many thread pitches are within 10mm. You can know how many pitches there are by dividing by 10mm. This way the measurement is more accurate.

The distance between two adjacent threads measured along the direction of the spiral. Generally refers to the axial distance between two corresponding points on the pitch line of two adjacent teeth on the thread in the thread pitch.

Extended information:

The pitch diameter, half angle and pitch error of the long screw are also often measured on a tool microscope. Precision screws also require measurement of helix error. Figure 3 shows the principle of the laser screw measuring instrument for measuring helix error. When the screw rotates through the angle θ, the circular grating rotating synchronously with the screw produces a number of moiré fringes equivalent to the angle θ.

The axial displacement of the helix is ??converted into the number of interference fringes by a laser length sensor through a measuring head and a right-angle prism installed on the floating support plate.

The two optical signals are converted into electrical signals through their respective photoelectric conversion elements. After amplification, shaping, frequency division and phase comparison, the error curve is recorded by the recorder, from which the pitch error can also be obtained. . It can measure lead screws with level 5 accuracy of 1 meter and level 6 accuracy of 2 meters. Commonly used thread gauges are made by the pass-stop method.

Baidu Encyclopedia-Thread Measurement