The mold is specially designed and the casting will remain in the active part when the mold is opened. In this way, the movable part of the putter will push out the casting. The putter is usually driven by the platen. It will accurately drive all the putter at the same time with the same force, so as to guarantee that the casting will not be damaged. When the casting is pushed out, the pressure plate shrinks to pull back all the push rods for the next die-casting. Since the casting is still at high temperature when it is unmoulded, only the number of push rods is enough to ensure the average pressure on each push rod is small enough to avoid damage to the casting. However, the putter will still leave a mark, so careful design must be made so that the position of the putter does not affect the operation of the casting too much.