During measurement, it is important to stop using the knob when the micrometer screw is approaching the object to be measured, and instead use the fine adjustment knob to avoid excessive pressure, which can both ensure accurate measurement results and protect the spiral micrometer When reading, pay attention to whether the half millimeter mark on the fixed scale has been exposed.

The structural feature of a pointed external diameter micrometer is a pointed head with two measuring surfaces of 45 ° vertebral body shape. It is suitable for measuring the groove diameter of small grooves, such as drill bits, vertical milling cutters, even groove taps, and the diameter of the tooth root circle of clock gears.