Gravity cast aluminum parts: an option suitable for small and medium-sized production

2026-05-28 16:29:55

In casting production planning, batch size directly affects the selection of process routes. For small and medium-sized production (usually referring to an annual output of hundreds to tens of thousands of pieces), gravity cast aluminum parts are an economically viable option.

From the perspective of mold cost, gravity casting can use metal molds, sand molds, or shell molds. The initial cost of metal molds is lower than that of die-casting molds, about one-third to one-half of the latter, and mold modification and repair restoration are relatively simple. For sand gravity casting, the mold cost is lower, and even wooden or resin molds can be used, which is suitable for sample trial production or small batch orders with an annual output of less than a thousand pieces.

From the perspective of equipment investment, the purchase cost of gravity casting equipment (such as tilting casting machines, fixed pouring machines, or manual pouring turntables) is significantly lower than that of die-casting machines or low-pressure casting machines. The establishment cycle of a gravity casting production line is relatively short, and the requirements for infrastructure such as electricity and air pressure in the factory are relatively relaxed.

From the perspective of production flexibility, the mold replacement and process adjustment time for gravity casting is generally several hours to one day, which facilitates the rotation of different types of castings in the same production unit. For production modes that require multiple varieties, small batches, and short lead times, this rapid production change capability has practical significance.

In addition, the first piece verification cost of gravity cast aluminum parts is relatively low. When there is a design change, the cost of modifying the mold or remaking the sand core is controllable. Therefore, in the trial production stage, frequent product iterations, or insufficient annual production to dilute the cost of high-pressure molds, gravity casting often becomes a preferred molding method.