Screws are commonly used in our lives, and we have basically come into contact with them, but most people don't know much about the size measurement of precision miniature screws. I don't know how to measure, where to measure, what tool to use, and what unit is the value of the measure. Next, the screw manufacturers Hangzhou Lizhan Hardware Co., Ltd. will take you to learn the basic methods of precision micro screw measurement.
If you want to know the size of the screw, you need a measuring tool that is a vernier caliper. Because the unit of measurement of the screw is millimeter (mm), it is not accurate if you use a ruler or volume. Another is that we need to know which parts of the screw are to be measured. For example, the specification of a pan-head screw is M3*8, and the diameter of the threaded part must be measured first. The caliper will display at 3mm. The pitch of the thread, and then the length of the screw will be displayed in 8mm (note: the length of the pan head screw is not added to the head), so the approximate size of a screw can be measured.
Each dimension has a tolerance range, and the measured value is qualified as long as it is within the specified tolerance range. But the measurement of countersunk screws is different. The length of countersunk screws includes the head. The difference between the different measurement methods of flat head pan head screws and countersunk head screws. The length of the screw is represented by the letter L, the diameter of the mechanical tooth is represented by M, and the diameter of the self-tapping tooth is represented by ST.
The measurement method of precision micro screws I mentioned above is our unified method at present. With the continuous development of electronic products, the application of precision micro screws has become more common. People not only require miniature screws to be small in size, beautiful in appearance, and good in practicability.