Other parts in the mold include core slide and so on. A core is a part that opens or opens on a casting and can be used to add detail to the casting. There are three types of core: fixed, moving and loose. The direction of the stationary cores is parallel to the direction of the casting leaving the mold, and they are either fixed or permanently attached to the mold. Movable cores can be arranged in any direction other than the direction of release. The removable cores must be removed from the mold cavity by means of a separation device before the casting can be opened after solidification. The slider is very close to the movable core. The biggest difference is that the slider can be used to make the concave surface. The use of cores and sliders in die - casting increases costs significantly. Loose cores, also known as extractors, can be used to make complex surfaces, such as threaded holes. Before each cycle begins, the slider needs to be manually installed before it is finally pushed out with the casting. Then remove the loose core. Loose cores are the most expensive cores because it takes a lot of work to make and it increases cycle time.