The benefits of sand casting are numerous.For example:

• There are minimal restrictions on the shape, size, and material.
• The process is extremely efficient, and uses dry sand, green sand, or chemically bonded sand.
• Sand casting is a great alternative to die casting because it allows for low- or high-volume production.

Sand casting processes use sand-based molds to create custom designs and complex metal parts. The molds themselves are expendable after production, and the casting process works with nearly any metal alloy.

How Sand Casting Works

The sand casting process is carried out through the following six steps:

1. Creating the design pattern. Before creating the mold, our team can help create a reusable pattern. This preform helps plan the mold and product details. The pattern also allows for some thermal contraction during the process.
2. Adding metal delivery details to the design. The pattern must match the design specifications and incorporate carefully designed passages to allow molten metal into the mold during later stages. These gating and riser features ensure the alloy can entirely fill the mold before the metal starts to harden and that no complex detailing remains hollow or half-formed. They also drive thermal contraction factors to acceptable loss areas, allow for gas venting, and prevent errors in the actual product portion of the casting.
3. Creating the mold. Sand is a refractory material that stays stable at high temperatures—a beneficial property for a molding material. Sand also holds the weight of the alloy but allows for easy breakage after the casting hardens. Manufacturers can also form the sand into highly detailed, nonreactive molds.
4. Pouring the casting. Manufacturers use the in-mold metal delivery system to pour molten metal into the mold. The metal fills both the product portion and the gating and risers of the mold.
5. Shakeout processes. The molten metal needs to cool and harden for varying periods of time depending on the material, design complexity, and the method of cooling. Once the metal solidifies, operators break the sand mold to remove the finished product.
6. Finishing and final steps. During this stage, manufacturers apply all of the finishing steps to get the part ready for delivery or assembly. This includes cutting away the gates, risers, and runners, sand-blasting or grinding the metal to the required degree of smoothness, and any necessary machining.

Advantages and Applications

Advantages of using sand casting include:

• Low costs for equipment and tooling
• Recyclable excess material
• Easy forming of large or complex parts
• Short lead times
• Many material options

Some of the most common applications include the production of components such as:

• Engine blocks
• Engine manifolds
• Gears
• Pulleys

Impro’s Sand Casting and Production Capabilities

Impro’s experience in creating high-end, geometrically complex sand castings from high-grade materials is beyond comparison. With our experienced staff and state-of-the-art facilities, we offer both machine and manual molding operations for resin sand casting. We produce parts in low or high volumes and pour castings ranging from 0.5 kilograms to 20 tons. Our green sand castings range from 0.5–30 kilograms.

Impro’s inspection capabilities are top of the line. We offer on-site testing capabilities such as:

• Spectrographic and manual quantitative analysis
• Metallographic analysis
• Brinell, Rockwell and Vickers hardness inspection
• Mechanical property analysis
• Low and normal temperature impact testing
• Cleanliness inspection
• UT, MT, and RT inspection

We have made significant investments in top-grade inspection and testing equipment to ensure that we provide only the highest quality products. For example:

• Our Speck spectrometer checks 28 chemical elements.
• Our Zeiss metallurgical microscope produces high-resolution images 1,000 times magnified.
• Our Zeiss cleanliness meter determines particle size and quantity to ensure materials meet or exceed the international standard.
• We use GE ultrasonic detectors to discover flaws.
• We use X-ray machines and accelerators that can scan castings with 200 mm maximum wall thickness.

Our services are varied and extensive. We offer material advisory service and development, as well as advice from our technical experts on design and casting. We do 3D CAD drawings, simulations, and component machining. We also offer cavity fill, solidification, tension, and distortion services. We provide assembly, testing and qualification, heat treatment, and surface treatment. From start to finish, we have you covered every step of the way.

Learn More

Impro is dedicated to the quality of our work, and our commitment to excellence ensures the highest customer satisfaction. As a global leader in high-precision, high-complexity, and mission-critical casting and machined components, we strive to meet and exceed the needs of our customers. To learn more about our sand casting services and capabilities or to discuss options for your next project, reach out to the team today.