Foundries that make gears, pulleys, crankshafts or rods use the process of sand casting, an ideal way to make aluminum castings for parts that have odd shapes. Often the process is used to make the pieces that become large, heavy machines and automobile parts like engine blocks, transmissions and cylinder heads. Here are some advantages of using sand casting over other processes.
Material Choice Flexibility
Most metal operations choose sand casting because they can use any alloy, both those that contain iron and those that do not. That are other processes that use vacuuming to pour melted metals into casts, but the properties of some metals do not allow the vacuuming mechanism and require mere pouring into casts.
Low Tooling Costs
Depending on the material a foundry chooses for casts, including metal, wood or plastic, the cost of sand casting can be relatively low. The biggest concern in sand casting is always whether the pattern inside the mold will become worn and defect the shape of any castings. Foundries often see cost savings and more efficient sand casting on lower volumes repeated over long periods of time. Smaller cast volumes preserve the mold pattern and the use of a machine is patternless and less likely to wear down fast. Many foundries invest a more expensive upfront cost with machines and recoup their investment over time.
One of the biggest benefits of the sand casting process is how well the process adapts to almost any size, weight or shape for final casting. Typically, the process produces casts that weigh from a few ounces to more than 200 tons. Cast designers have no limits on the shape that the process will produce, so there is a wide range of possibilities. The only consistent requirement is the need for a machine for some part of the process. Nearly all castings have at least some surfaces that need a machine for composition. These surfaces either cannot tolerate some parts of the sand casting process or they need to be combined with other molded parts.
The process of sand casting can be designed to handle almost any volume. There are times the process will need to run to generate a single part. Sometimes, the tolerance of pieces and the shape that the process needs to be produced is more important than producing a large quantity of molds. This makes sand casting ideal for handling a wide range of aluminum mold needs.