Gravity casting is a process that produces non-ferrous alloy parts. It is sometimes referred to as permanent mold casting and is used on aluminum, zinc, or copper base alloys. It consists of three stages: pouring the molten material into the mold, cooling the molten metal, and removing the cast part. The process has several advantages.

Before pouring, the hot metal is coated with a refractory material that protects the casting and increases its life. Next, the gravity casting mold is closed with a clamp. The liquid metal flows into the mold cavity under gravity. After solidification, the casting is removed from the mold cavity. It is often used in combination with a riser to compensate for the shrinkage of the casting, which limits yield to 60 percent or less. The use of mechanical ejector pins, however, is sometimes necessary in situations where coatings are inadequate to protect the casting. These pins are placed in the mold and leave a small round impression on the casting.

A second advantage of gravity casting is its high filling capacity. The mold is designed to fill thin sections, reducing the amount of air required. This helps in reducing the production costs and avoiding scrap. The mold is pre-heated to a temperature between 200 and 280 degrees. Then, a liquid metal of a desired composition is poured into it. When the metal has cooled down, it solidifies. When the casting is ready, the gate systems and risering systems are separated from the casting. The mold is then cleaned and ready for the next casting process.

Gravity casting is one of the oldest processes of metal fabrication. It is the process that uses the force of gravity to pour the metal into a mold. Most other processes use forced pressure or natural pressure difference to force the metal into the mold. In the case of aluminum and other lightweight alloys, this method is especially useful. A gravity casting mold is also reusable for similar parts. This method is a cost-effective way of producing multiples of the same part.

One important feature of gravity casting is that the mold is designed to minimize surface defects. This is done by insulating the mold's cavity with a heat-insulating coating material. This coating layer prevents the formation of wrinkle-like surface defects. In the case of a gravity casting mold, the outer peripheral portion of the mold is enlarged, so that the molten metal flows slowly through the cavity.

Gravity casting molds have many advantages over high-pressure die casting molds. The molds can be made more precise, with wall thicknesses as low as 4mm. The molds can also be heat-treated, making them more durable. One of the biggest benefits of gravity casting molds is that they have high productivity and yield. They are also a great way to reduce labor costs.