The first step of sand casting involves the placement of the mold pattern in sand. The size and shape of the casting is directly influenced by the mold. Therefore, manufacturing companies must create new molds to create metal products and components in specific sizes and shape.
Most casting processes involve the use of a gating system, and sand casting is no exception. Consisting of a pouring cup and tunnels or “gates” to the mold, it’s used to funnel the molten mold into the mold cavity. After placing the mold pattern in sand, manufacturing companies will set up a gating system such as this.
With the gating system set up, manufacturing companies can then remove the mold pattern from the sand. The mold pattern is no longer relevant at this point. When the mold pattern is placed inside sand, the sand takes its shape. As a result, the mold pattern can be removed.
Now it’s time to pour the molten metal into the mold cavity. Sand casting supports a variety of different metals and alloys, some of which include iron, steel, aluminum, bronze, magnesium, zinc and tin. Depending on the specific metal or alloy used, manufacturing companies may need to heat it up to 3,000 degrees Fahrenheit. Once the metal or alloy has turned from a solid state to a liquid state, it’s poured into the mold cavity.
After the molten metal has been poured into the mold cavity, manufacturing companies must wait for it to cool. Again, different types of metal take different lengths of time to cool. As the molten metal cools, it will revert from a liquid state back to a solid state.
The sixth and final step of sand casting involves breaking open the mold to remove the newly created metal casting. While molds patterns are typically reusable, the actual molds are not. Therefore, manufacturing companies must recreate a new mold each time they want to create a new metal product or component using sand casting.