Core Prints, Core Location, Core Shift, Core venting, and Chaplets

The core is a material used in molding to provide a hollow portion of casting which cannot be made by pattern alone. Mold should have a provision to give sufficient grip between this core and the mold; the universally followed and easiest method is the provision of core print where possible. Various types of core prints are used to support all kinds of the core. The size of this core print is to be provided depends upon the requirement of fine details on the casting. Even though it is a part of the pattern, it never appears on casting.

Core location and core shift

The location of the core is important in casting. It must place in a particular position. Shifting of the core from its original position during casting may cause a displaced cavity. The result of this is the defects in the final product.

Chaplets

Chaplets are used to support the core inside the mold cavity and ensure there is no displacement in its position. The chaplets should be made of the material want to be cast.

Core venting

Adequate venting of the core should be provided to escape the gasses evolved during casting. Core venting is a secondary function of Core. The core is vented by providing holes in the core by the inclusion of wax strips. The large cores are made hollow by inserting metal pipes inside the core.

Read: Types of Pattern material - Application, advantages and limitation