Since water is solidification of metal so it can be moved. If the inner metal cylinder, water solidifies, it can not be moved. Because the broken pieces.
Due to the metal water has not frozen, so it can move. If water, metal inside the bore began solidifying, unable to move because it will make the piece broken.
because the water is not firm enough so that the metal can be made to move within metal cylinder. If the water freezes, and then do not start because they will be able to move pieces, broken.