The caliper is mainly used to measure the external dimensions of cylindrical, rectangular, polygonal and other workpieces. During measurement, if the through end of the caliper can pass through the workpiece but the end cannot, it indicates that the workpiece is qualified. Special sizes can be customized and processed according to customer requirements.

When using a caliper to inspect a workpiece, try to inspect it from above the shaft as much as possible. Hold the caliper by hand and make it perpendicular to the axis of the tested shaft. Without applying pressure, slide it over the outer circle of the shaft based on the weight of the caliper itself. When inspecting from a horizontal direction, gently slide the end of the caliper over the shaft. Do not forcefully clamp the caliper onto the shaft, as this will cause the two claws to bounce outwards and deform, leading to the accidental removal of the shaft that exceeds its size; And the working surface of the caliper must be subjected to wear and tear; Even due to excessive force, the caliper may deform and become unusable. For workpieces, the tested surface will be damaged, especially for copper and aluminum products which are severely affected. Try not to inspect the shaft diameter horizontally as much as possible, as this may result in less sensitive hand sensation and difficulty in controlling the applied pressure during inspection.

When using a caliper to check the end, it is only allowed to be placed on one side of the shaft. If it cannot slide over, it is considered qualified for inspection.

The working surface of the caliper is in short contact with the workpiece. In order to obtain accurate inspection results, the open and closed ends of the caliper should be inspected at least at four positions along or around the axis.