The mold used to obtain the appearance of the casting is called a pattern, and the mold used to obtain the inner cavity of the casting is called a core box. Sometimes the core made of a core box can also be used to obtain the appearance of the casting. According to the manufacturing method and the material used in the core box, it can be divided into three types: wood mold, metal mold and plastic mold.

. Wooden mold. A pattern made of wood and a core box. Light wood, easy to shape, short production cycle and low cost. However, it is not durable and easily deformed. It is the most common pattern material used in single or small production.

. Metal mold. A pattern and a core box made of a metal material. Commonly used metal materials are aluminum alloy, copper alloy and gray cast iron. Aluminum alloy is the most commonly used metal material because of its light weight, easy processing and rusting.

. Plastic mold. The ability of the plastic mold is between the wood mold and the metal mold.

In real production, the use of wood molds is widespread. Because the wood mold is transformed into a mold cavity, the structure of the wood mold must be concerned with the characteristics of forging. For convenience of taking the mold, the slope (called draft angle) should be made on the wall of the wood mold perpendicular to the parting surface; the joint between the upper wall and the wall of the wood mold should be rounded; in the spare parts On the processing part, it is necessary to leave the excess metal layer (called machining allowance) cut during the cutting process, and the size of the wooden mold is much larger than the size of the spare parts (called the shrinkage allowance). There is a hole in the spare part, the solid mold is non-porous on the wooden mold, and a piece is raised (called the core head). It can be seen that the wood mold and the spare parts are separate. Therefore, the wood mold is generally not directly manufactured according to the spare parts drawings, but the parts drawing is based on the forging process design, and the forging process drawing is drawn. Remanufacturing wood molds and core boxes.

The above tooling (patterns and core boxes, etc.) must be used to maintain their accuracy when used, such as spring sand to prevent them from rubbing against their surfaces; immediately after brushing or lifting the core box, clean them with a brush and wipe them with cotton yarn. Otherwise, the mold type (core) sand is not easy to clean after air drying. When the hard object is cleaned, the running surface is scraped: after use, it is packed and placed on the rack to prevent moisture.

Large and complex parts often rely on multiple sand cores and sand-type sections to form their geometric shapes. When the lower core is used, it is necessary to use the template to check the positional dimensions between them. Complex sand cores are often made in blocks, sometimes they must be assembled with a lower core clamp and then lowered into the cavity.