sprue

Sprue is the channel through which molten material, such as metal or plastic, flows from the mold's inlet into the main cavity during manufacturing. It serves as a conduit allowing the material to fill the mold evenly. Proper design of the sprue is essential for efficient and defect-free casting or molding, as it impacts flow rate, fill time, and the quality of the final product. After the material cools and solidifies, the sprue is removed, leaving the shaped item behind.