The water grinder should be called the electromagnetic sucker of the water grinder. It is the abbreviation of rectangular standard electromagnetic sucker, because it is mainly equipped in water grinder (ordinary surface grinder is called water grinder because of the large cooling water flow of grinding wheel), and the suction force is 100 Newton per square centimeter. Its work is dirty, but its income is considerable. As for learning CNC milling machine, according to personal ability or hobby, you can recruit apprentices everywhere, depending on whether you dare to try!