Constant RongZhong for each brand clock movement is widely applicable Such as seiko movement, the sun's movement, constant RongZhong stopwatch, surplus, etc., clock needle hole shape more than circular hole and square hole. Heng rong clock clock needle made of copper, aluminum material and plastic three kinds of material, the thickness of the metal clock needle, respectively is 0.4 to 1.0 mm, the thickness of the plastic clock needle from 1.5 to 2.0 mm, which is widely used in metal clock needle is the thickness of 0.4 mm, 0.4 mm thickness in a normal clock can completely meet the requirements, eedle don't recommend more than 0.5 mm thick because it will have a certain influence on movement of life and the accuracy of travel time. Constant RongZhong needle length measuring method is from the center of the Zhong Kong amount, rather than the whole a clock the length of the needle, because this method is according to the size of the clock dial radius quickly know how long this clock need clock needle.